Article
Astronomy & Astrophysics
Madison Smith, L. van Zee, D. A. Dale, L. C. Hunter, S. Staudaher, T. Wrock
Summary: This study presents global, radial, and local photometric measurements of several nearby low-mass galaxies. It uses multiwavelength observations to trace the distributions of old and young stars and derive their star formation histories. The results show that bluer UV sources in galaxies with recent star formation are clustered on smaller scales, while the reddest UV sources are not clustered on any scale. Additionally, a negative radial gradient in the star formation history parameter is found, indicating inside-out growth of galactic discs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. Querejeta, E. Schinnerer, S. Meidt, J. Sun, A. K. Leroy, E. Emsellem, R. S. Klessen, J. C. Munoz-Mateos, H. Salo, E. Laurikainen, I Beslic, G. A. Blanc, M. Chevance, D. A. Dale, C. Eibensteiner, C. Faesi, A. Garcia-Rodriguez, S. C. O. Glover, K. Grasha, J. Henshaw, C. Herrera, A. Hughes, K. Kreckel, J. M. D. Kruijssen, D. Liu, E. J. Murphy, H-A Pan, J. Pety, A. Razza, E. Rosolowsky, T. Saito, A. Schruba, A. Usero, E. J. Watkins, T. G. Williams
Summary: We investigated the impact of different environments on the molecular gas content, star formation rate, and depletion time in 74 nearby galaxies. Our findings suggest that the stellar structures in galaxies strongly affect the organization of molecular gas and star formation, but have a more subtle impact on star formation efficiency.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Kirsten L. Larson, Janice C. Lee, David A. Thilker, Bradley C. Whitmore, Sinan Deger, James Lilly, Rupali Chandar, Daniel A. Dale, Frank Bigiel, Kathryn Grasha, Brent Groves, Stephen Hannon, Ralf S. Klessen, Kathryn Kreckel, J. M. Diederik Kruijssen, Adam K. Leroy, Hsi-An Pan, Erik Rosolowsky, Eva Schinnerer, Andreas Schruba, Elizabeth J. Watkins, Thomas G. Williams
Summary: We developed a method to identify stellar associations using HST NUV-U-B-V-I imaging and applied it to two galaxies in the PHANGS-HST survey. Our algorithm successfully characterizes the properties of the associations and provides a more complete census of recent star formation activity. Younger associations correlate closely with H ii regions, while older associations show an anti-correlation with H α emission.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Justus Neumann, Daniel Thomas, Claudia Maraston, Daniel Goddard, Jianhui Lian, Lewis Hill, Helena Dominguez Sanchez, Mariangela Bernardi, Berta Margalef-Bentabol, Jorge K. Barrera-Ballesteros, Dmitry Bizyaev, Nicholas F. Boardman, Niv Drory, Jose G. Fernandez-Trincado, Richard Lane
Summary: This study analyzes over 2.6 million spatial bins from 7439 nearby galaxies in the SDSS-IV MaNGA survey and identifies a significant relation between mass density and metallicity with contributions from different radial distances. Metallicity increases with radius independently of morphology in low- and intermediate-mass galaxies, while high-mass galaxies only show this radial dependence in high-density regions of spiral galaxies. The findings suggest a driving factor for metallicity that promotes chemical enrichment in the outer parts of galaxies more strongly than in the inner parts, potentially involving scenarios such as gas accretion, outflows, recycling, and radial migration.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
L. Cortese, A. Fraser-McKelvie, J. Woo, B. Catinella, K. E. Harborne, J. van de Sande, J. Bland-Hawthorn, S. Brough, J. J. Bryant, S. Croom, S. Sweet
Summary: In this study, the correlation between stellar surface density (sigma(1)) and the proxy for stellar spin parameter (lambda(re)) was investigated for 1599 nearby galaxies. The results showed that changes in sigma(1) were mirrored by changes in lambda(re) on the star-forming main sequence, but not below it. Passive galaxies were found to be more heterogeneous in terms of their structure compared to star-forming galaxies and may have followed different evolutionary paths.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Oleg Egorov, Tatiana A. Lozinskaya, Konstantin Vasiliev, Anastasiya D. Yarovova, Ivan S. Gerasimov, Kathryn Kreckel, Alexei Moiseev
Summary: The study presents the results of a multiwavelength analysis of the nearby dwarf galaxy DDO 53, revealing a large ionized gas supershell and anomalous H I features in the north part of the galaxy. These findings suggest a connection with gas accretion from the intergalactic medium or a past merger event, impacting on the star formation activity in the brightest region of DDO 53.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
G. Orellana-Gonzalez, P. Cerulo, G. Covone, C. Cheng, R. Leiton, R. Demarco, M-L Gendron-Marsolais
Summary: In this study, we investigated the star-formation activity in a sample of approximately 56,000 brightest cluster galaxies (BCGs) using optical and infra-red data. We found that star-forming BCGs are more abundant and have higher star-formation rates (SFR) at higher redshifts compared to lower redshifts. We also observed variations in the fraction of star-forming BCGs depending on BCG stellar mass and cluster halo mass. Additionally, our results suggest a correlation between star formation and the cooling of the intracluster medium.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. E. Watkins, H. Salo, E. Laurikainen, S. Diaz-Garcia, S. Comeron, J. Janz, A. H. Su, R. Buta, E. Athanassoula, A. Bosma, L. C. Ho, B. W. Holwerda, T. Kim, J. H. Knapen, S. Laine, K. Menendez-Delmestre, R. F. Peletier, K. Sheth, D. Zaritsky
Summary: The Spitzer Survey of Stellar Structure in Galaxies (S(4)G) is a detailed study of over 2300 nearby galaxies in the near-infrared, which has been critical to our understanding of the detailed structures of nearby galaxies. A follow-up Spitzer survey was conducted to add early-type galaxies (ETGs) to the sample and analyze them in a consistent manner. The results show various scaling relations among the derived parameters and highlight differences between ETGs and late-type galaxies (LTGs).
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Ristea, L. Cortese, A. Fraser-McKelvie, S. Brough, J. J. Bryant, B. Catinella, S. M. Croom, B. Groves, S. N. Richards, J. van de Sande, J. Bland-Hawthorn, M. S. Owers, J. S. Lawrence
Summary: Misalignments between the rotation axis of stars and gas are an indication of external processes shaping galaxies throughout their evolution. Kinematically decoupled features are more prevalent in early-type/passive galaxies compared to late-type/star-forming systems. Star formation is the main source of gas ionization in only 22 per cent of misaligned galaxies; 17 per cent are Seyfert objects, while 61 per cent show Low-Ionization Nuclear Emission-line Region features. When considering only misalignments driven by accretion, the acquired gas is feeding active star formation in only similar to 1/4 of cases.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Rogerio Riffel, Luis G. Dahmer-Hahn, Rogemar A. Riffel, Thaisa Storchi-Bergmann, Natacha Z. Dametto, Richard Davies, Leonard Burtscher, Marina Bianchin, Daniel Ruschel-Dutra, Claudio Ricci, David J. Rosario
Summary: We used NIFS and other equipment to study the stellar population of 18 nearby Seyfert galaxies in the inner few hundred parsecs and found a significant fraction of young to intermediate-age stellar populations. The study also revealed correlations between the stellar population properties and other properties of the galaxies, such as the X-ray luminosity and the contributions from hot dust, featureless continuum, and reddening. Additionally, there was a delayed relationship between the mass-weighted mean age of the stellar population and the triggering/feeding of the active galactic nuclei (AGN), and the gas reaching the supermassive black hole may originate from the mass loss of intermediate-age stellar populations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jennifer A. Hardwick, Luca Cortese, Danail Obreschkow, Barbara Catinella, Robin H. W. Cook
Summary: We present a detailed study of the stellar mass versus specific angular momentum relation for a sample of 564 nearby galaxies. Our results show that the slope and scatter of the Fall relation vary when considering galaxy type and sample selection. The gas fraction is the most correlated parameter for low stellar masses, while the bulge-to-total ratio becomes more dominant at higher masses. Interestingly, when only the disc components of galaxies are considered, the gas fraction remains the most correlated parameter with the scatter of the relation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Justus Neumann, Daniel Thomas, Claudia Maraston, Lewis Hill, Lorenza Nanni, Oliver Wenman, Jianhui Lian, Johan Comparat, Violeta Gonzalez-Perez, Kyle B. Westfall, Renbin Yan, Yanping Chen, Guy S. Stringfellow, Matthew A. Bershady, Joel R. Brownstein, Niv Drory, Donald P. Schneider
Summary: This article presents the Mapping Nearby Galaxies at Apache Point Observatory survey (MaNGA) firefly Value Added Catalogue (VAC), which contains spatially resolved stellar population properties of approximately 3.7 million nearby galaxies from the final data release of the MaNGA survey. The study utilizes the spectral fitting code firefly to derive parameters such as stellar ages, metallicities, masses, star formation histories, star formation rates, and dust attenuation. Two variants of the VAC are provided, using different stellar population models, and they show slight differences in stellar ages, metallicities, and color excesses. Additionally, the article compares the stellar masses from firefly with those from other catalogues, finding that firefly masses match best with those from the NSA catalogue.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Adriano Poci, Russell J. Smith
Summary: In this study, we compare the mass estimates derived from independent modelling techniques based on the relative proximity of the nearby strong-lens galaxy SNL-1. Our results show that SNL-1 has a constant intermediate triaxiality at all radii, and occupies the most-compact edge on the mass-size plane. We also investigate how the observed lensing configuration is affected by the orientation of the lens galaxy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
L. N. Makarova, D. Makarov
Summary: Using observations from the Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS), the star formation histories (SFHs) of isolated dwarf spheroidal (dSph) galaxies were homogeneously measured, revealing complex SFHs with stars formed 10-13 billion years ago and middle-aged stars (1-8 billion years). A comparative analysis of SF parameters of nearest dSphs in different environments suggests a possible spatial segregation effect on their evolution scenario.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
A. Maragkoudakis, E. Peeters, A. Ricca
Summary: This study examines the variations in spectral characteristics and intensities of polycyclic aromatic hydrocarbons (PAHs) in two different scenarios of PAH processing: destruction of small PAHs or formation of large PAHs, and vice versa. PAH emission was measured with and without plateau components. The results show that smaller PAHs have a larger impact on the PAH band strengths, and smaller PAHs primarily contribute to plateau emission. The 7.7/(11.0 + 11.2) μm PAH band ratio is the best choice for tracing PAH charge, and the 3.3/(11.2 + 11.0) μm PAH band ratio is efficient for both tracing PAH size and characterizing the dominant processing or formation scenario.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Giulia Santucci, Sarah Brough, Jesse van de Sande, Richard M. McDermid, Glenn van de Ven, Ling Zhu, Francesco D'Eugenio, Joss Bland-Hawthorn, Stefania Barsanti, Julia J. Bryant, Scott M. Croom, Roger L. Davies, Andrew W. Green, Jon S. Lawrence, Nuria P. F. Lorente, Matt S. Owers, Adriano Poci, Samuel N. Richards, Sabine Thater, Sukyoung Yi
Summary: Dynamical models are essential for understanding the internal dynamics of galaxies, but many current results are based on axisymmetry, which may not represent a significant fraction of massive galaxies. By constructing triaxial Schwarzschild orbit-superposition models using data from the SAMI Galaxy Survey, we found that changes in internal structures are correlated with total stellar mass, with most galaxies being oblate. Higher mass galaxies are more likely to be non-oblate, with evidence of different kinematic signatures and orbit combinations.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Sarah A. Bird, Xiang-Xiang Xue, Chao Liu, Chris Flynn, Juntai Shen, Jie Wang, Chengqun Yang, Meng Zhai, Ling Zhu, Gang Zhao, Hai-Jun Tian
Summary: Using stellar halo samples, this study estimates the mass distribution and dark matter mass of the Milky Way through two methods. The results show reasonable consistency across different samples and methods.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Pablo M. Galan-de Anta, M. Sarzi, A. Pillepich, Y. Ding, L. Zhu, L. Coccato, E. M. Corsini, K. Fahrion, J. Falcon-Barroso, D. A. Gadotti, E. Iodice, M. Lyubenova, I Martin-Navarro, R. M. McDermid, F. Pinna, G. van de Ven, P. T. de Zeeuw
Summary: In this study, the evolution of kinematically defined stellar discs in Fornax-like clusters from the IllustrisTNG simulations was investigated. It was found that very few stellar discs survive in such dense environments, which is consistent with the survival rates observed in other massive clusters. However, the low number of present-day disc galaxies in Fornax-like clusters contradicts the presence of edge-on disc galaxies observed in the actual Fornax cluster. Additionally, the comparison of stellar population properties revealed that some disc galaxies in Fornax have unique features that cannot be matched by any disc galaxies in the simulations. These findings suggest the need for future studies on passive cluster spirals to further understand cosmological simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Michael J. Greener, Alfonso Aragon-Salamanca, Michael Merrifield, Thomas Peterken, Elizaveta Sazonova, Roan Haggar, Dmitry Bizyaev, Joel R. Brownstein, Richard R. Lane, Kaike Pan
Summary: We archaeologically investigate the evolution of metallicity in both stellar and gaseous components of spiral galaxies of differing masses using SDSS-IV MaNGA survey data. We directly measure the metallicity evolution of the stellar component by analyzing absorption-line spectra and infer the variation in gas metallicity over cosmic time based on the established relationship between gas metallicity, stellar mass, and star formation rate. Our analysis of 1619 spiral galaxies reveals that the metallicity of lower-mass galaxies increases together in both stellar and gaseous components, while in higher-mass systems, the average stellar metallicity does not increase in step with the inferred gas metallicity and actually decreases over time.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Shuang Zhou, Michael Merrifield, Alfonso Aragon-Salamanca, Joel R. Brownstein, Niv Drory, Renbin Yan, Richard R. Lane
Summary: This study aims to quantify the subtle differences in the evolution of disc galaxies based on their environment, focusing on isolated galaxies, central galaxies in a group, and satellite galaxies. The findings show significant differences, particularly in low-mass galaxies, with low-mass satellites having a shorter period of star formation and chemical enrichment, while central galaxies have more extended histories and greater retention of gas.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Xiao Cao, Yan-Mei Chen, Yong Shi, Min Bao, Alexei Moiseev, Dmitry Bizyaev, Song-Lin Li, Jose G. Fernandez-Trincado, Rogemar A. Riffel, Rogerio Riffel, Richard R. Lane
Summary: The discovery of two galaxies with two misaligned gas disks challenges the traditional understanding of gas accretion and angular momentum accumulation in galaxies. The large differences in kinematic position angles between the gas disks and the stellar components suggest multiple gas acquisition events at low redshift, highlighting the complexity of galactic evolution and gas origins.
Article
Astronomy & Astrophysics
Chengqun Yang, Ling Zhu, Behzad Tahmasebzadeh, Xiang-Xiang Xue, Chao Liu
Summary: In this study, the orbits and distribution characteristics of halo stars in the Milky Way were investigated within a distance range of 5 to 50 kpc. It was found that the density distribution of the stellar halo can be well described by a double-broken power-law function, with shallower slopes in the inner regions and flatter slopes in the outer regions. The study also revealed the presence of relative metal-rich stars in the inner 10 kpc.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
M. Bernardi, R. K. Sheth, H. Dominguez Sanchez, B. Margalef-Bentabol, D. Bizyaev, R. R. Lane
Summary: Gradients in the stellar populations in galaxies, including age, metallicity, and stellar initial mass function, can result in changes in the stellar-mass-to-light ratio. Understanding these gradients is important for determining the distribution of stellar mass and light in galaxies, especially considering the variations in age, metallicity, and IMF.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Grecco A. Oyarzun, Kevin Bundy, Kyle B. Westfall, Ivan Lacerna, Renbin Yan, J. R. Brownstein, Niv Drory, Richard R. Lane
Summary: This study combines a sample of over 3000 galaxies to analyze the relationship between the central and satellite formation and the mass of the galaxy and host halo. By analyzing spectral features, it reveals the formation history and environmental impact on galaxies.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Keith Hawkins, Adrian M. M. Price-Whelan, Allyson A. A. Sheffield, Aidan Z. Z. Subrahimovic, Rachael L. L. Beaton, Vasily Belokurov, Denis Erkal, Sergey E. E. Koposov, Richard R. R. Lane, Chervin F. P. Laporte, Christian Nitschelm
Summary: Using astrometry from ESA's Gaia mission and radial velocity information from the SDSS-IV APOGEE survey, we identified up to 13 stars that are likely members of the Orphan-Chenab stream. Our study reveals that the stars in the stream do not belong to a single metallicity population and have a median metallicity of -1.92 dex with a dispersion of 0.28 dex. The chemical pattern of these stars suggests that the progenitor of the OC stream is likely to be a dwarf spheroidal galaxy with a mass of around 10^6 solar masses.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Caleb I. Canas, Chad F. Bender, Suvrath Mahadevan, Dmitry Bizyaev, Nathan De Lee, Scott W. Fleming, Fred Hearty, Steven R. Majewski, Christian Nitschelm, Donald P. Schneider, Javier Serna, Keivan G. Stassun, Gudmundur Stefansson, Guy S. Stringfellow, John C. Wilson
Summary: We have characterized 28 low-mass companions to Kepler objects of interest (KOIs), which were detected as transiting companions to Sunlike stars by the Kepler mission. Using the APOGEE-N, we confirm these companions as single-lined spectroscopic binaries and derive fundamental parameters for them. The APOGEE-N data provide reliable radial velocities and enable detailed characterization of individual systems and the inference of orbital elements for faint KOIs.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
Wenting Wang, Ling Zhu, Yipeng Jing, Robert J. J. Grand, Zhaozhou Li, Xiaoting Fu, Lu Li, Jiaxin Han, Ting S. Li, Fabo Feng, Carlos Frenk
Summary: We investigated the impact of binary orbital motions on the dynamical modeling of dwarf galaxies and found that binary motions lead to inflated total masses and deflated central densities. The inflation in total masses is more significant for higher binary fractions, while the central density deflation is weakly dependent on the binary fraction. Observational errors tend to weaken the deflation in central density.
ASTROPHYSICAL JOURNAL
(2023)
Correction
Astronomy & Astrophysics
Caleb I. Canas, Chad F. Bender, Suvrath Mahadevan, Dmitry Bizyaev, Nathan De Lee, Scott W. Fleming, Fred Hearty, Steven R. Majewski, Christian Nitschelm, Donald P. Schneider, Javier Serna, Keivan G. Stassun, Gudmundur Stefansson, Guy S. Stringfellow, John C. Wilson
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
Danilo Gonzalez-Diaz, Jose G. Fernandez-Trincado, Sandro Villanova, Doug Geisler, Beatriz Barbuy, Dante Minniti, Timothy C. Beers, Christian Moni Bidin, Francesco Mauro, Cesar Munoz, Baitian Tang, Mario Soto, Antonela Monachesi, Richard R. Lane, Heinz Frelijj
Summary: This study analyzed six red giant stars in the globular cluster NGC 6558 using high-resolution near-infrared spectra, finding an average metallicity of -1.15 with no metallicity spread. Solar Ni abundance was found to be around +0.01, with moderate enhancements of alpha-elements and s-process element Ce, along with significant nitrogen enrichment and low carbon levels.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
