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
Mira Seo, Hong Bae Ann
Summary: We present the star formation histories (SFHs) of early-type dwarf galaxies, dSphs and dEs, in the local Universe within z = 0.01. The SFHs of early-type dwarf galaxies are characterized by pre-enriched, metal-poor old stellar populations, absence of moderately old stars that have ages of a few Gyr. There are some differences in the SFHs of dSphs and dEs. In particular, dSphs formed old (greater than or similar to 10 Gyr old) metal-poor stars similar to 2 times more than dEs. The effects of reionization and feedback from supernova explosions are thought to be strong enough to remove the gas left, which prevent moderately old stellar populations in dSphs. In contrast, the ejected gases are not completely removed from dEs and fall back to ignite burst of star formation at a few Gyr after the first period of violent bursts of star formation, showing a suppression of star formation at lookback time approximate to 9.6 Gyr. The second peak of star formation at lookback time approximate to 4.5 Gyr in dEs produces moderately old stellar populations. Distinction between dSphs and dEs is useful to examine the SFHS of the early-type dwarfs since the cumulative SFHs are most closely related to their morphology. The stellar mass plays an important role in the SFHs of the early-type dwarfs as a driver of star formation, especially in galaxies with primordial origin.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
M. Romano, A. Nanni, D. Donevski, M. Ginolfi, G. C. Jones, I. Shivaei, Junais, D. Salak, P. Sawant
Summary: The physical properties of star-formation-driven outflows in a sample of 29 local dwarf galaxies were characterized in this study. Atomic outflow signatures were detected in the high-velocity tails of 11 sources, while weaker outflows were detected in the average stacked spectrum. The outflow rates were found to be comparable to the star-formation rates of the galaxies, with a significant amount of gas escaping into the intergalactic medium (IGM).
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
James W. Johnson, Charlie Conroy, Benjamin D. Johnson, Annika H. G. Peter, Phillip A. Cargile, Ana Bonaca, Rohan P. Naidu, Turner Woody, Yuan-Sen Ting, Jiwon Jesse Han, Joshua S. Speagle
Summary: We have modeled the stellar abundances and ages of two disrupted dwarf galaxies in the Milky Way stellar halo and found similarities with other galaxies in terms of stellar mass and chemical evolution. Our fitting method is accurate and applicable to any one-zone model.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Nikhil Arora, Andrea Maccio, Stephane Courteau, Tobias Buck, Noam Libeskind, Jenny G. Sorce, Chris B. Brook, Yehuda Hoffman, Gustavo Yepes, Edoardo Carlesi, Connor Stone
Summary: Recent studies of dwarf galaxies in the Local Group have revealed their unique characteristics in star formation history, stellar metallicity, gas content, and kinematics. Simulation results show that Local Group dwarf galaxies have similar total gas mass and stellar properties compared to field galaxies. However, they have more cold gas in their central parts and more metal-rich gas in the halo, likely due to interactions with other dwarfs in the high-density environment of the Local Group. Metal diffusion does not significantly impact the chemical evolution of Local Group dwarf galaxies. These findings highlight the importance of studying the stellar components of Local Group dwarfs for understanding galaxy formation.
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
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
Madison Smith, L. van Zee, S. Salim, D. Dale, S. Staudaher, T. Wrock, A. Maben
Summary: By fitting spectral energy distributions of nearby galaxies, this study examines the star formation histories and rate tracers at different scales. The analysis of brightness profiles and radial SED fitting reveals population gradients in stellar discs and haloes. The results show a wide variety of star formation gradients and average stellar age distributions in these galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Katja Fahrion, Teodora-Elena Bulichi, Michael Hilker, Ryan Leaman, Mariya Lyubenova, Oliver Muller, Nadine Neumayer, Francesca Pinna, Marina Rejkuba, Glenn van de Ven
Summary: Nuclear star clusters (NSCs) formation depends on the mass of the galaxies. Low-mass NSCs predominantly form from the merger of globular clusters (GCs) in dwarf galaxies, while high-mass NSCs in massive galaxies assemble through central enriched star formation. Spectral analysis of nine nucleated late-type dwarf galaxies shows that NSCs in low-mass galaxies mainly grow through the inspiral of GCs, while central star formation can contribute to NSC growth in more massive galaxies.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
N. Kovakkuni, F. Lelli, P-A Duc, M. Boquien, J. Braine, E. Brinks, V. Charmandaris, F. Combes, J. Fensch, U. Lisenfeld, S. S. McGaugh, J. C. Mihos, M. S. Pawlowski, Y. Revaz, P. M. Weilbacher
Summary: Research reveals that some star-forming regions in tidal dwarf galaxies (TDGs) resemble normal spiral galaxies, while others exhibit characteristics of extreme starbursts.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
P. Bonfini, A. Zezas, M. L. N. Ashby, S. P. Willner, A. Maragkoudakis, K. Kouroumpatzakis, P. H. Sell, K. Kovlakas
Summary: The study uses the Star Formation Reference Survey to constrain the mass distribution in nearby star-forming galaxies and measure the integrated luminosity density and total stellar mass density. The results indicate that discs dominate the mass density budget and recent star formation primarily happened in massive systems within the discs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
V Rusakov, M. Monelli, C. Gallart, T. K. Fritz, T. Ruiz-Lara, E. J. Bernard, S. Cassisi
Summary: Through detailed analysis, we found that the star formation history of the Fornax galaxy exhibits sharp bursts and intermittent activity, with differences between different regions, suggesting that tidally induced star formation may be the cause of this phenomenon.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Matthew Pereira-Wilson, Julio F. Navarro, Alejandro Benitez-Llambay, Isabel Santos-Santos
Summary: In this study, the role of the cosmic UV background in regulating star formation in low-mass Lambda CDM haloes has been examined using the APOSTLE cosmological simulations. The results show that star formation primarily occurs in haloes whose mass exceeds a redshift-dependent 'critical' mass, determined by the structure of the haloes and the thermal pressure of UV-heated gas. The discovery of a population of faint field dwarfs lacking ongoing star formation would provide strong support for these findings.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
R. M. Gonzalez Delgado, J. E. Rodriguez-Martin, L. A. Diaz-Garcia, A. de Amorim, R. Garcia-Benito, G. Martinez-Solaeche, P. A. A. Lopes, M. Maturi, E. Perez, R. Cid Fernandes, A. Cortesi, A. Finoguenov, E. R. Carrasco, A. Hernan-Caballero, L. R. Abramo, J. Alcaniz, N. Benitez, S. Bonoli, A. J. Cenarro, D. Cristobal-Hornillos, J. M. Diego, R. A. Dupke, A. Ederoclite, J. A. Fernandez-Ontiveros, C. Lopez-Sanjuan, A. Marin-Franch, I Marquez, C. Mendes de Oliveira, M. Moles, I Pintos, L. Sodre, K. Taylor, J. Varela, H. Vazquez Ramio, J. M. Vilchez
Summary: This study demonstrates the potential of J-PAS in detecting and characterizing galaxy populations within galaxy clusters, showing that the proportion of red and quiescent galaxies in clusters increases with stellar mass, while the abundance excess of transition galaxies is modest at lower stellar masses.
ASTRONOMY & ASTROPHYSICS
(2022)
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
Maya Silverman, James S. Bullock, Manoj Kaplinghat, Victor H. Robles, Mauro Valli
Summary: In this study, properties of Milky Way subhaloes in self-interacting dark matter models were explored using high-resolution zoom-in N-body simulations. The number and distribution of subhaloes within the host halo were found to be similar for cross-sections of 1-5 cm(2) g(-1), and they agreed with observations of Milky Way satellite galaxies under the condition that subhaloes with peak circular velocity >7 km s(-1) could form galaxies. No distinctive signatures were found in the pericentre distribution of the subhaloes that could differentiate between the models. Analytical modeling showed that subhaloes with cross-sections between 1 and 5 cm(2) g(-1) were not dense enough to match the densest ultrafaint and classical dwarf spheroidal galaxies in the Milky Way. This motivates further exploration of velocity-dependent cross-sections with values larger than 5 cm(2) g(-1) at relevant velocities.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Michael Y. Grudic, Zachary Hafen, Carl L. Rodriguez, David Guszejnov, Astrid Lamberts, Andrew Wetzel, Michael Boylan-Kolchin, Claude-Andre Faucher-Giguere
Summary: This study introduces a new method for modeling cluster formation in galaxy simulations by mapping giant molecular clouds (GMCs) to a cluster population. The researchers find that about 10% of stars in the galaxy form in gravitationally bound clusters, and this fraction increases in regions with higher gas density and star formation rate due to denser GMCs. The properties of star clusters and their formation vary systematically over the galaxy's history, and the mass function of bound clusters does not follow a single distribution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Tibor Dome, Anastasia Fialkov, Philip Mocz, Bjoern Malte Schaefer, Michael Boylan-Kolchin, Mark Vogelsberger
Summary: In this study, cosmological N-body simulations were used to investigate high-redshift dark matter haloes and their responsiveness to an FDM-like power spectrum cutoff. FDM-like haloes were found to have lower concentrations, more elongated shapes, and stronger alignment correlations compared to CDM haloes. These FDM-like features are expected to be strikingly visible in the high-z Universe.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jiaqi (Martin) Ying, Brian Chaboyer, Emily M. Boudreaux, Catherine Slaughter, Michael Boylan-Kolchin, Daniel Weisz
Summary: We constructed 20,000 sets of theoretical isochrones through Monte Carlo simulation to measure the absolute age of the globular cluster M92. By generating simulated Hess diagrams and fitting them to observational data, we found that M92 has an age of 13.80 +/- 0.75 Gyr.
ASTRONOMICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Erin Mentuch Cooper, Karl Gebhardt, Dustin Davis, Daniel J. J. Farrow, Chenxu Liu, Gregory Zeimann, Robin Ciardullo, John J. J. Feldmeier, Niv Drory, Donghui Jeong, Barbara Benda, William P. P. Bowman, Michael Boylan-Kolchin, Oscar A. Chavez Ortiz, Maya H. H. Debski, Mona Dentler, Maximilian Fabricius, Rameen Farooq, Steven L. L. Finkelstein, Eric Gawiser, Caryl Gronwall, Gary J. J. Hill, Ulrich Hopp, Lindsay R. R. House, Steven Janowiecki, Hasti Khoraminezhad, Wolfram Kollatschny, Eiichiro Komatsu, Martin Landriau, Maja Lujan Niemeyer, Hanshin Lee, Phillip MacQueen, Ken Mawatari, Brianna McKay, Masami Ouchi, Jennifer Poppe, Shun Saito, Donald P. P. Schneider, Jan Snigula, Benjamin P. P. Thomas, Sarah Tuttle, Tanya Urrutia, Laurel Weiss, Lutz Wisotzki, Yechi Zhang
Summary: We release the first catalog of sources obtained from the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX), which is a spectroscopic survey designed to measure the Hubble expansion parameter and angular diameter distance. The catalog includes a large number of Ly alpha-emitting galaxies and [O ii]-emitting galaxies, as well as stars, low-redshift galaxies, and active galactic nuclei. It provides comprehensive information on the identified sources, including coordinates, redshifts, line identifications, classification information, line fluxes, and spectra.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Anna T. P. Schauer, Michael Boylan-Kolchin, Katelyn Colston, Omid Sameie, Volker Bromm, James S. Bullock, Andrew Wetzel
Summary: We study the impact of supersonic streaming velocities on the formation of dwarf galaxies at z greater than or similar to 5. Our cosmological hydrodynamic simulations show that while star formation is delayed and the number of luminous galaxies is suppressed in the streaming runs compared to nonstreaming runs, these effects decay with time. By z = 5, the properties of the simulated galaxies are nearly identical in the two sets of simulations, indicating that the effects of streaming velocities on galaxies do not persist to z = 0.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Andrew Wetzel, Christopher C. Hayward, Robyn E. Sanderson, Xiangcheng Ma, Daniel Angles-Alcazar, Robert Feldmann, T. K. Chan, Kareem El-Badry, Coral Wheeler, Shea Garrison-Kimmel, Farnik Nikakhtar, Nondh Panithanpaisal, Arpit Arora, Alexander B. Gurvich, Jenna Samuel, Omid Sameie, Viraj Pandya, Zachary Hafen, Cameron Hummels, Sarah Loebman, Michael Boylan-Kolchin, James S. Bullock, Claude-Andre Faucher-Giguere, Dusan Keres, Eliot Quataert, Philip F. Hopkins
Summary: We have released a public data set of cosmological zoom-in simulations of galaxy formation from the FIRE project. The simulations achieve high resolution and accurately model various phenomena such as stellar evolution and feedback. The data includes snapshots of different types of galaxies across different redshift ranges, as well as accompanying catalogs and python packages for analysis.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
Sijie Yu, James S. Bullock, Alexander B. Gurvich, Zachary Hafen, Jonathan Stern, Michael Boylan-Kolchin, Claude-Andre Faucher-Giguere, Andrew Wetzel, Philip F. Hopkins, Jorge Moreno
Summary: In this study, the formation of Milky Way-mass galaxies is investigated using FIRE-2 ?CDM cosmological zoom-in simulations, focusing on the orbital evolution of stars formed in the main progenitor of the galaxy. The stars are classified into isotropic spheroid, thick-disc, and thin-disc components based on their orbital circularities, and it is shown that these components are assembled in a time-ordered sequence. The early bursty phase of star formation is followed by a late-time steady phase, coinciding with the virialization of the inner CGM. Stars born during the bursty phase evolve into an isotropic spheroidal population, while the majority of thick-disc stars form during a clumpy-disc 'spin-up' phase. Late-time star formation occurs on circular orbits within a narrow plane, leading to the population of thin discs. The age distributions of the spheroid, thick disc, and thin disc populations are self-similarly scaled with the steady-phase transition time, suggesting a link between morphological age dating and CGM virialization time.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Philip Mocz, Anastasia Fialkov, Mark Vogelsberger, Michael Boylan-Kolchin, Pierre-Henri Chavanis, Mustafa A. Amin, Sownak Bose, Tibor Dome, Lars Hernquist, Lachlan Lancaster, Matthew Notis, Connor Painter, Victor H. Robles, Jesus Zavala
Summary: We investigate cosmological structure formation in fuzzy dark matter (FDM) with attractive self-interaction using numerical simulations. The attractive self-interaction arises if the FDM boson is an ultra-light axion with a strong CP symmetry-breaking scale. Despite its weakness, the attractive self-interaction can counteract quantum pressure and modify structure formation. Our simulations show that the self-interaction enhances small-scale structure formation and soliton cores undergo a phase transition from dilute to dense solitons above a critical mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Omid Sameie, Michael Boylan-Kolchin, Philip F. Hopkins, Andrew Wetzel, Xiangcheng Ma, James S. Bullock, Kareem El-Badry, Eliot Quataert, Jenna Samuel, Anna T. P. Schauer, Daniel R. Weisz
Summary: Cosmological hydrodynamical simulations were conducted to study the formation of proto-globular cluster candidates in progenitors of present-day dwarf galaxies. It was found that self-bound stellar clusters form in progenitors with a certain mass, triggered by the compressive effects of supernova feedback or cloud-cloud collisions. These clusters can survive for a few billion years, with the longest-lived ones forming at a significant distance from their host galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Robert Feldmann, Eliot Quataert, Claude-Andre Faucher-Giguere, Philip F. Hopkins, Onur Catmabacak, Dusan Keres, Luigi Bassini, Mauro Bernardini, James S. Bullock, Elia Cenci, Jindra Gensior, Lichen Liang, Jorge Moreno, Andrew Wetzel
Summary: We have introduced a suite of cosmological volume simulations to study galaxy evolution. The principal simulation, FIREbox, captures the multiphase nature of the interstellar medium in a fully cosmological setting and provides a representative sample of galaxies. By validating the simulation predictions against observational data, we find that the properties of simulated galaxies broadly agree with observations, but there are some discrepancies at late times. Despite this, FIREbox offers a baseline prediction of galaxy formation theory and highlights modeling challenges for future galaxy simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Alessandro Savino, Daniel R. Weisz, Evan D. Skillman, Andrew Dolphin, Andrew A. Cole, Nitya Kallivayalil, Andrew Wetzel, Jay Anderson, Gurtina Besla, Michael Boylan-Kolchin, Thomas M. Brown, James S. Bullock, Michelle L. M. Collins, M. C. Cooper, Alis J. Deason, Aaron L. Dotter, Mark Fardal, Annette M. N. Ferguson, Tobias K. Fritz, Marla C. Geha, Karoline M. Gilbert, Puragra Guhathakurta, Rodrigo Ibata, Michael J. Irwin, Myoungwon Jeon, Evan N. Kirby, Geraint F. Lewis, Dougal Mackey, Steven R. Majewski, Nicolas Martin, Alan McConnachie, Ekta Patel, R. Michael Rich, Joshua D. Simon, Sangmo Tony Sohn, Erik J. Tollerud, Roeland P. van der Marel
Summary: We present the lifetime star formation histories (SFHs) for six ultrafaint dwarf (UFD) satellite galaxies of M31 based on deep color-magnitude diagrams constructed from Hubble Space Telescope imaging. We find that most UFDs formed a significant portion of their stellar mass by z = 5, but one UFD formed a majority of its stellar mass in a rapid burst at z similar to 2-3. This discovery challenges the notion that all UFDs are quenched by reionization, as predicted by cosmological simulations.
ASTROPHYSICAL JOURNAL
(2023)