Article
Astronomy & Astrophysics
Isabel M. E. Santos-Santos, Laura Sales, Azadeh Fattahi, Julio F. Navarro
Summary: The abundance of faintest galaxies sheds light on dark matter nature and dwarf galaxy formation. This study explores two potential models for the relation between stellar mass and halo mass at the faint end, providing important insights into the mechanisms of galaxy formation in these systems.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Christopher C. Lovell, Stephen M. Wilkins, Peter A. Thomas, Matthieu Schaller, Carlton M. Baugh, Giulio Fabbian, Yannick Bahe
Summary: This study introduces a new method using a machine learning framework to explore the relationship between galaxies and dark matter halos in the universe, enabling predictions of galaxy properties at a lower computational cost. By training the model in different environments, researchers can infer the bias of galaxy evolution, allowing application to larger volumes of dark-matter-only simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Kyle A. Oman
Summary: This study presents the most precise determination to date of the number density of extragalactic 21-cm radio sources. The analysis is based on the H I velocity width function (H I WF) of 21,827 sources from the Arecibo Legacy Fast ALFA survey. The results show that the shape of the H I WF is remarkably similar in different sky regions, indicating its potential as a stable tracer of the mass function of dark matter haloes and as a constraint on cosmological models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Daisuke Toyouchi, Kohei Inayoshi, Miho N. Ishigaki, Nozomu Tominaga
Summary: Recent observations of active galactic nuclei (AGNs) have shown a high Fe II/Mg II line-flux ratio in their broad-line regions, nearly independent of redshift up to z greater than or similar to 6. The high flux ratio requires rapid production of iron in galactic nuclei to reach an abundance ratio of [Fe/Mg] greater than or similar to 0.2 as high as those observed in matured galaxies in the local universe. We propose a possible explanation of rapid iron enrichment in AGNs by massive star formation that follows a top-heavy initial mass function (IMF) with a power-law index of Gamma larger than the canonical value of Gamma = -2.35 for a Salpeter IMF. Taking into account metal production channels from different types of SNe, we find that the high value of [Fe/Mg] greater than or similar to 0.2 requires the IMF to be characterized with Gamma greater than or similar to -1 (Gamma greater than or similar to 0) and a high-mass cutoff at M-max similar or equal to 100-150 M-circle dot (M-max greater than or similar to 250 M-circle dot). Given the conditions, core-collapse SNe with M-* greater than or similar to 70 M-circle dot and pair-instability SNe give a major contribution for iron enrichment. Such top-heavy stellar IMFs would be a natural consequence from mass growth of stars formed in dense AGN discs under Bondi-like gas accretion that is regulated by feedback at M-* greater than or similar to 10 M-circle dot. The massive stellar population formed in AGN discs also leave stellar-mass black hole remnants, whose mergers associated with gravitational-wave emission account for at most 10 per cent of the merger rate inferred from LIGONirgo observations to simultaneously explain the high [Fe/Mg] ratio with metal ejection.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. R. Calette, Aldo Rodriguez-Puebla, Vladimir Avila-Reese, Claudia del P. Lagos
Summary: By seeding semi-empirical galaxies into a large N-body dark matter simulation, we extend the local stellar galaxy-(sub)halo connection to the atomic hydrogen component. The relation between the atomic hydrogen mass and dark matter mass is not a monotonic increasing function, but rather increases within a certain mass range before slightly decreasing. The bivariate distribution of atomic hydrogen and dark matter mass is broad and bimodal, impacted by the initial conditions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Christoph Engler, Annalisa Pillepich, Anna Pasquali, Dylan Nelson, Vicente Rodriguez-Gomez, Kun Ting Eddie Chua, Eva K. Grebel, Volker Springel, Federico Marinacci, Rainer Weinberger, Mark Vogelsberger, Lars Hernquist
Summary: The study reveals a remarkable level of diversity and host-to-host scatter in the abundance of satellite galaxies around MW/M31-like hosts in TNG50, with the number and properties of satellites being influenced by factors such as host galaxy stellar mass and halo mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Dali Zhang, Yu Luo, Xi Kang, Han Qu
Summary: The distribution of satellite galaxies in a host galaxy is influenced by the cumulative accretion of subhaloes and star formation efficiency, providing valuable information about dark matter and galaxy formation physics. The observed luminosity gap in galaxies like M101 may be due to differences in subhalo mass rather than stochastic star formation processes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Paul Goudfrooij, Randa S. Asa'd
Summary: This paper explores the impact of star cluster mass on the accuracy and precision of age and metallicity determination in simple stellar populations (SSPs) using the full-spectrum fitting technique. The study compares simulated spectra of star clusters across different mass ranges with SSP model spectra in various wavelength regimes to determine best-fitting ages and metallicities. The research highlights the significance of the mid-IR wavelength regime in identifying young massive clusters in dusty star-forming regions in distant galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
M. Sharma, M. J. Page, A. A. Breeveld
Summary: We present measurements of the rest-frame ultraviolet (UV) galaxy luminosity function (LF) and luminosity density (LD) in the wavelength of far-UV (1500 angstrom) for a redshift range of z = 0.6- 1.2. Our results suggest an increase in star formation activity between redshifts z = 0.7 and z = 1. We also find that the faint-end slope at z = 0.7 is shallower compared to previous studies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Viraj Manwadkar, Andrey Kravtsov
Summary: By using the GRUMPY model to forward model dwarf galaxy formation and evolution, we found that the luminosity and distance distributions of model satellites are consistent with those measured in surveys. Additionally, the model can simultaneously reproduce the observed distribution of stellar half-mass radii of MW satellites and the overall r(1/2)-M-* relation observed in dwarf galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
L. Wang, F. Gao, P. N. Best, K. Duncan, M. J. Hardcastle, R. Kondapally, K. Malek, I McCheyne, J. Sabater, T. Shimwell, C. Tasse, M. Bonato, M. Bondi, R. K. Cochrane, D. Farrah, G. Guerkan, P. Haskell, W. J. Pearson, I Prandoni, H. J. A. Roettgering, D. J. B. Smith, M. Vaccari, W. L. Williams
Summary: By cross-matching Herschel sources and LOFAR sources, this study provides the most accurate estimate to date of the bright end of the infrared luminosity functions and the abundance of hyperluminous IR galaxies with IR luminosities >10(13)L(circle dot). The results show a good agreement with previous studies and indicate that the population of HLIRGs has surface densities with variations due to a combination of the applied flux limit and cosmic variance.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. J. Page, T. Dwelly, I McHardy, N. Seymour, K. O. Mason, M. Sharma, J. A. Kennea, T. P. Sasseen, J. Rawlings, A. A. Breeveld, I Ferreras, N. S. Loaring, D. J. Walton, M. Symeonidis
Summary: The study utilized UV imaging data from the XMM-Newton Optical Monitor telescope to measure UV luminosity functions of galaxies with redshifts between 0.6 and 1.2, supplemented by optical and infrared imaging for photometric redshifts. The results indicated that the characteristic absolute magnitude M * is brighter for the redshift range 0.8 < z < 1.2 compared to 0.6 < z < 0.8.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Peter A. Thomas, Christopher C. Lovell, Maxwell G. A. Maltz, Aswin P. Vijayan, Stephen M. Wilkins, Dimitrios Irodotou, William J. Roper, Louise Seeyave
Summary: The upcoming deep galaxy surveys with JWST will investigate galaxy evolution during the epoch of reionization. It is important to understand survey variance to evaluate the representativeness of the galaxy populations in these studies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Steven R. Furlanetto, Jordan Mirocha
Summary: Over the past three decades, photometric galaxy selection using the Lyman-break technique has revolutionized our understanding of the high-z Universe, providing large and relatively uncontaminated samples of galaxies at 3 < z < 8. With the JWST, this technique has been extended to z ~ 17, but the purity of the resulting samples has not been tested. A simple model based on the dark matter halo mass function reveals a dramatic rise in contamination at z > 10, especially for luminous galaxies, necessitating careful selection processes and potentially extensive spectroscopic follow-up campaigns.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Nicha Leethochawalit, Guido Roberts-Borsani, Takahiro Morishita, Michele Trenti, Tommaso Treu
Summary: We determine the bright end of the rest-frame UV luminosity function (UVLF) at z = 8-10 by selecting bright z greater than or similar to 8 photometric candidates from the largest systematic compilation of HST (pure-)parallel observations to date, the Super-Brightestof-Reionizing-Galaxies (SuperBoRG) data set. We identify 31 z greater than or similar to 8 candidates via colour selection and photo- z analysis with observed magnitude (24.1 < H-160 < 26.6) and 1 sigma range probability of 58-95 per cent of being true high-z galaxies. Following detailed completeness and source recovery simulations, as well as modelling of interloper contamination, we derive rest-frame UVLFs at z = 8-10 down to M-UV similar or equal to -23.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Kai Hoffmann, Yi Mao, Jiachuan Xu, Houjun Mo, Benjamin D. Wandelt
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2019)
Article
Astronomy & Astrophysics
Xinkai Chen, Jing Wang, Xu Kong, Barbara Catinella, Li Shao, Houjun Mo
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2020)
Article
Chemistry, Physical
Shunkai Li, Shukai Cheng, Liwu Mo, Min Deng
Article
Physics, Multidisciplinary
Hao-Ran Yu, Pavel Motloch, Ue-Li Pen, Yu Yu, Huiyuan Wang, Houjun Mo, Xiaohu Yang, Yipeng Jing
PHYSICAL REVIEW LETTERS
(2020)
Article
Astronomy & Astrophysics
Shuang Zhou, H. J. Mo, Cheng Li, Mederic Boquien, Graziano Rossi
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2020)
Article
Astronomy & Astrophysics
Kai Wang, H. J. Mo, Cheng Li, Jiacheng Meng, Yangyao Chen
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2020)
Article
Astronomy & Astrophysics
Fu-Heng Liang, Cheng Li, Niu Li, Shuang Zhou, Renbin Yan, Houjun Mo, Wei Zhang
Summary: The research shows a positive correlation between the high-mass slope of the stellar initial mass function and stellar metallicity, with steeper initial mass functions preferred at higher metallicities. This correlation remains consistent even when binary population models are considered.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Renjie Li, Huiyuan Wang, H. J. Mo, Shuiyao Huang, Neal Katz, Xiong Luo, Weiguang Cui, Hao Li, Xiaohu Yang, Ning Jiang, Yuning Zhang
Summary: This study investigates the properties and evolution of intergalactic and intracluster media in different types of the cosmic web using reconstructed initial conditions and constrained hydrodynamic simulations. The simulations reveal that warm-hot intergalactic gas is primarily associated with filaments in the local cosmic web, and there is a strong correlation between gas temperature and the strength of the local tidal field. The simulations also predict the presence of discontinuities related to shock fronts and contact edges.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Xiao Li, Cheng Li, H. J. Mo, Ting Xiao, Jing Wang
Summary: We present a new H I mass estimator that provides unbiased H I mass estimates for optical samples like SDSS. We apply this estimator to study the H I mass function of local galaxies and the H I-halo mass relation. Our results show that the discrepancies between different measurements are primarily caused by cosmic variance.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Xuanyi Wu, Houjun Mo, Cheng Li, Seunghwan Lim
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Pengfei Li, Huiyuan Wang, H. J. Mo, Enci Wang, Hui Hong
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Fu-Heng Liang, Cheng Li, Niu Li, Renbin Yan, Houjun Mo, Wei Zhang, Camilo Machuca, Alexandre Roman-Lopes
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Jingjing Shi, Huiyuan Wang, Houjun Mo, Mark Vogelsberger, Luis C. Ho, Min Du, Dylan Nelson, Annalisa Pillepich, Lars Hernquist
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Niu Li, Cheng Li, Houjun Mo, Jian Hu, Shuang Zhou, Cheng Du
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Yangyao Chen, H. J. Mo, Cheng Li, Huiyuan Wang, Xiaohu Yang, Youcai Zhang, Kai Wang
ASTROPHYSICAL JOURNAL
(2020)