Article
Astronomy & Astrophysics
Philippa S. Cole, Joseph Silk
Summary: The production and existence of primordial black holes can impact the primordial power spectrum and matter power spectrum, potentially leading to observable effects on the 21 cm power spectrum. It is crucial to include the contribution from primordial fluctuations in predicting the 21 cm signal in order to avoid underestimation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
B. Novosyadlyj, Yu. Kulinich, B. Melekh, V. Shulga
Summary: This study examines the formation and destruction of the first molecules during the Dark Ages and Cosmic Dawn, evaluating the luminosity of protogalaxy clumps (halos) in molecular lines. The impact of photodissociation processes on molecules like H-2 and HD is significant before full reionization, while the number density of helium hydride ions HeH+ shows complicated dependences on halo kinetic temperature and models of the first light. The brightness temperature evolution of individual halos in rotational lines of certain molecules does not exceed microkelvin, but detection could provide important insights into physical processes during the formation of the first stars and galaxies.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Yuxiang Qin, J. Stuart B. Wyithe, Pascal A. Oesch, Garth D. Illingworth, Ecaterina Leonova, Simon J. Mutch, Rohan P. Naidu
Summary: This study investigates the Ly alpha IGM transmission and environment of bright galaxies during the epoch of reionization. It reveals that brighter galaxies are less affected by damping-wing absorption, while the transmission of fainter galaxies depends on UV luminosity. The brightest sources are located in the largest ionized regions, leading to a lower incidence of Ly alpha detection in fainter galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Hyunbae Park, Paul R. Shapiro, Kyungjin Ahn, Naoki Yoshida, Shingo Hirano
Summary: Recent studies have shown that recombination in small-scale gas clouds can affect the history of cosmic reionization, and the streaming velocity has a significant impact on local reionization history, especially as the ionizing efficiency of galaxies decreases.
ASTROPHYSICAL JOURNAL
(2021)
Article
Multidisciplinary Sciences
Guido Roberts-Borsani, Tommaso Treu, Wenlei Chen, Takahiro Morishita, Eros Vanzella, Adi Zitrin, Pietro Bergamini, Marco Castellano, Adriano Fontana, Karl Glazebrook, Claudio Grillo, Patrick L. Kelly, Emiliano Merlin, Themiya Nanayakkara, Diego Paris, Piero Rosati, Lilan Yang, Ana Acebron, Andrea Bonchi, Kit Boyett, Marusa Bradac, Gabriel Brammer, Tom Broadhurst, Antonello Calabro, Jose M. Diego, Alan Dressler, Lukas J. Furtak, Alexei V. Filippenko, Alaina Henry, Anton M. Koekemoer, Nicha Leethochawalit, Matthew A. Malkan, Charlotte Mason, Amata Mercurio, Benjamin Metha, Laura Pentericci, Justin Pierel, Steven Rieck, Namrata Roy, Paola Santini, Victoria Strait, Robert Strausbaugh, Michele Trenti, Benedetta Vulcani, Lifan Wang, Xin Wang, Rogier A. Windhorst
Summary: In the early universe, sources of ultraviolet photons played a crucial role in ionizing intergalactic hydrogen, making the universe transparent to UV radiation. Fainter galaxies that are surrounded by neutral gas were believed to dominate the photon budget. By using the James Webb Space Telescope and gravitational lensing, the ultra-faint galaxy JD1 was spectroscopically confirmed at a redshift of z = 9.79, showing a compact and complex morphology with low stellar mass and subsolar metallicity.
Article
Astronomy & Astrophysics
James E. Davies, Rupert A. C. Croft, Tiziana Di-Matteo, Bradley Greig, Yu Feng, J. Stuart B. Wyithe
Summary: The study uses BLUETIDES simulation to investigate the measurement of ionized regions around bright galaxies at the beginning of reionization. They find that with proper foreground subtraction, a 5 sigma detection of these regions can be made with 30 images around some of the brightest galaxies in the simulation. Additionally, the study shows that reducing foreground contamination in Fourier space can significantly improve the detection of ionized regions at redshift z=9.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Max Gronke, Pierre Ocvirk, Charlotte Mason, Jorryt Matthee, Sarah E. Bosman, Jenny G. Sorce, Joseph Lewis, Kyungjin Ahn, Dominique Aubert, Taha Dawoodbhoy, Ilian T. Iliev, Paul R. Shapiro, Gustavo Yepes
Summary: The study utilized a radiation hydrodynamic simulation to calculate the Lyman-alpha transmission properties of the intergalactic medium at redshifts ranging from 5.8 to 7, confirming a decline in Lyman-alpha transmission with redshift and a rapid decline in blue transmission at higher redshifts.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Keir K. Rogers, Hiranya Peiris
Summary: The study presents a general framework for obtaining robust bounds on the nature of dark matter using cosmological N-body simulations and Lyman-alpha forest data. They construct an emulator of hydrodynamical simulations, which is a flexible and accurate model for predicting the response of the Lyman-alpha forest flux power spectrum to different dark matter models, the state of the intergalactic medium, and the primordial power spectrum. The framework can be optimized for the analysis of many other dark matter candidates and demonstrates a powerful approach for robust and computationally efficient inference from the cosmic large-scale structure.
Article
Astronomy & Astrophysics
Ewald Puchwein, James S. Bolton, Laura C. Keating, Margherita Molaro, Prakash Gaikwad, Girish Kulkarni, Martin G. Haehnelt, Vid Irsic, Tomas Soltinsky, Matteo Viel, Dominique Aubert, George D. Becker, Avery Meiksin
Summary: We introduce the Sherwood-Relics simulations, which are a new set of large cosmological hydrodynamical simulations designed to model the intergalactic medium (IGM) during and after the cosmic reionization of hydrogen. This suite includes over 200 simulations covering a wide range of astrophysical and cosmological parameters, and incorporates a new lightweight hybrid scheme for handling radiative transfer effects. Using this hybrid technique, we investigate the impact of patchy cosmic reionization on the spatial fluctuations in IGM properties, and find that it causes long-lasting temperature fluctuations and increases the Lyman-alpha forest flux power spectrum on large scales.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Koki Kakiichi, Joseph F. Hennawi, Yoshiaki Ono, Akio K. Inoue, Masami Ouchi, Richard S. Ellis, Romain A. Meyer, Sarah Bosman
Summary: We propose a new technique called photometric IGM tomography to map the intergalactic medium (IGM) at z=4.9 in the COSMOS field. This technique uses deep narrow-band imaging to detect Ly a forest transmission in background galaxies and locate Ly a emitters in the same cosmic volume. By measuring the Ly a forest transmission and analyzing the cross-correlation and autocorrelation functions, we provide observational constraints on the large-scale fluctuations of the IGM around Ly a emitters at z=4.9. The reconstructed 2D tomographic map of the IGM offers insights into early galaxy evolution and its relation to the large-scale cosmic web.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Raghunath Ghara, Sambit K. Giri, Benedetta Ciardi, Garrelt Mellema, Saleem Zaroubi
Summary: The MWA team obtained new upper limits on the power spectrum of the 21-cm signal at 6.5-8.7 redshifts and used Bayesian inference to constrain the ionization and thermal state of the IGM, revealing no constraints on IGM state above 7.8 redshift in the absence of an additional radio background. The results suggest that models with an IGM fraction of ionized regions below 0.6 and average gas temperature less than or equal to 10(3) h(-1) are disfavored, along with an exclusion of an additional radio background of at least 0.008% of the CMB at 1.42 GHz within the same credible interval limits.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Hiroyuki Tashiro, Kenji Kadota
Summary: The study demonstrates that CMB data can provide stringent bounds on the allowed PBH fraction in DM scenarios consisting of WIMPs and PBHs. The constraints from CMB data may be comparable to or even tighter than those from gamma-ray data, depending on the DM masses. Analysis using the Planck CMB data suggests that the PBH DM fraction with respect to the total dark matter is less than or similar to O(10(-10) to 10(-8)) for certain WIMP masses.
Article
Astronomy & Astrophysics
Tomas Soltinski, James S. Bolton, Nina Hatch, Martin G. Haehnelt, Laura C. Keating, Girish Kulkarni, Ewald Puchwein, Jonathan Chardin, Dominique Aubert
Summary: Late end of reionization at redshift z similar or equal to 5.3 is consistent with observed spatial variations in the Ly alpha forest transmission and the deficit of Ly alpha emitting galaxies around extended Ly alpha absorption troughs at z = 5.5. Strong 21-cm forest absorbers are predicted to persist until z = 6 in a model with only modest IGM pre-heating. A null-detection of 21-cm forest absorbers at z similar or equal to 6 with SKA1-low or possibly LOFAR could provide valuable lower limit information on the soft X-ray background at high redshift and the temperature of the pre-reionization IGM.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Heyang Long, Catalina Morales-Gutierrez, Paulo Montero-Camacho, Christopher M. Hirata
Summary: This article investigates the impact of inhomogeneous reionization on post-reionization 21-cm intensity mapping and discusses the prospects of capturing this effect in experiments. The study finds that the inhomogeneous reionization effect can significantly affect the H i power spectrum and cosmological parameter estimation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Paulo Montero-Camacho, Yuchen Liu, Yi Mao
Summary: It has been shown that the astrophysics of reionisation can be extracted from the Ly alpha forest power spectrum. However, the current approach of marginalizing over the memory of reionisation is model-dependent and computationally expensive. In this study, a simple analytical template is proposed to marginalize over the impact of cosmic reionisation in a model-independent manner.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)