Article
Astronomy & Astrophysics
Alexander Beckettt, Simon L. Morris, Michele Fumagalli, Nicolas Tejos, Buell Jannuzi, Sebastiano Cantalupo
Summary: We use H i absorption to model potential disc and outflow structures in the circumgalactic medium, and find possible outflows and co-rotating structures, suggesting that geometric cuts are not sufficient to distinguish between discs and outflows in single line-of-sight studies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Martin Wendt, Nicolas F. Bouche, Johannes Zabl, Ilane Schroetter, Sowgat Muzahid
Summary: The study investigates the dust content of the circum-galactic medium (CGM) in relation to the position of quasar sightlines with respect to the galaxy major-axis. It finds a positive correlation between the azimuthal angle and [Zn/Fe], indicating that CGM along the minor axis is on average more metal enriched compared to the gas located along the major axis. This anisotropic distribution is consistent with recent results on outflow and accretion in hydro-dynamical simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Sowgat Muzahid, Joop Schaye, Sebastiano Cantalupo, Raffaella Anna Marino, Nicolas F. Bouche, Sean Johnson, Michael Maseda, Martin Wendt, Lutz Wisotzki, Johannes Zabl
Summary: The first characterization of the circumgalactic medium of Ly alpha emitters (LAEs) reveals distinct features in terms of luminosity and interstellar material absorption, with no strong dependence of absorption on transverse distance, redshift, or Ly alpha emission line properties. However, a correlation is found between increased absorption near LAEs with higher star formation rates, suggesting a link between surrounding interstellar hydrogen and star formation in LAEs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Pratyush Anshul, Anand Narayanan, Sowgat Muzahid, Alexander Beckett, Simon L. Morris
Summary: This study presents the physical properties, chemical abundances, and transverse sizes of a multiphase medium in a galaxy field at z = 0.399 using HST/COS spectra of the twin quasar lines of sight Q 0107-025A & Q 0107-025B. The absorber towards Q 0107-025B is a partial Lyman limit system (pLLS) while the absorber along the other sightline has a lower HI column density. OVI and broad HI coinciding in both sightlines are best explained through collisional ionization in a cooling plasma with solar metallicity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Huanqing Chen, Rupert A. C. Croft, Nickolay Y. Gnedin
Summary: In this study, a convolutional neural network (CNN) method is used to recover the temperature distribution around quasars and estimate their lifetimes. The results show that the simple CNN can accurately recover the temperature profile with an accuracy of approximately 1400K in an idealized case. However, observational noise poses a significant challenge and can reduce the accuracy to approximately 2340K even with high signal-to-noise spectra.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. D. Amaral, T. Vernstrom, B. M. Gaensler
Summary: Researchers conducted an analysis on the statistical characteristics of weak magnetic fields in the intergalactic medium, but did not detect a significant correlation signal. They determined model-dependent upper limits on the parallel magnetic field strength of filaments in the IGM, and noted that these results are consistent with previous findings.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Thomas J. Cooper, Gwen C. Rudie, Hsiao-Wen Chen, Sean D. Johnson, Fakhri S. Zahedy, Mandy C. Chen, Erin Boettcher, Gregory L. Walth, Sebastiano Cantalupo, Kathy L. Cooksey, Claude-Andre Faucher-Giguere, Jenny E. Greene, Sebastian Lopez, John S. Mulchaey, Steven Penton, Patrick Petitjean, Mary E. Putman, Marc Rafelski, Michael Rauch, Joop Schaye, Robert A. Simcoe
Summary: This study investigates two partial Lyman limit systems (pLLSs) discovered in the Cosmic Ultraviolet Baryon Survey (CUBS), providing detailed information on the ionization analysis of multiphase gas in diverse galaxy environments. The data reveal kinematically aligned gas components with varying chemical abundances and densities, stressing the importance of considering the heterogeneous nature of circumgalactic gas in theoretical models. Additionally, survey data point to these systems being located near star-forming galaxies, highlighting the significance of studying the gas surrounding galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Zhijie Qu, Hsiao-Wen Chen, Gwen C. Rudie, Fakhri S. Zahedy, Sean D. Johnson, Erin Boettcher, Sebastiano Cantalupo, Mandy C. Chen, Kathy L. Cooksey, David DePalma, Claude-Andre Faucher-Giguere, Michael Rauch, Joop Schaye, Robert A. Simcoe
Summary: This paper presents a systematic study of the photoionization and thermodynamic properties of the cool circumgalactic medium (CGM) around galaxies at redshift z less than or similar to 1, providing important insights into the gas density, temperature, and pressure of individual absorbing components and their non-thermal motions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Margherita Molaro, Vid Irsic, James S. Bolton, Maggie Lieu, Laura C. Keating, Ewald Puchwein, Martin G. Haehnelt, Matteo Viel
Summary: Inhomogeneous reionization increases the power spectrum of the 1D Ly alpha forest at large scales at redshifts z >= 4. This is due to coherent fluctuations in the ionized hydrogen fraction resulting from large-scale variations in post-reionization gas temperature. An analysis of Ly alpha forest power spectrum measurements at 4.0 <= z <= 4.6 suggests a preference for a large-scale enhancement, potentially indicating inhomogeneous reionization. Future power spectrum measurements with lower uncertainties should provide more conclusive evidence for this enhancement.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Sean Morrison, Matthew M. Pieri, Debopam Som, Ignasi Perez-Rafols
Summary: The study investigates large-scale UV background inhomogeneities associated with high redshift quasar populations by measuring metal absorption in quasar absorption spectrum stacking. Stronger high ionization species absorption is observed closer to quasars at 2.4 < z < 3.1. Additionally, weak signs of increasing homogeneity with time are explored in the range of 2.05 < z < 2.4. Limitations of incomplete quasar samples are noted in the interpretation of results.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Lydia Stofanova, Aurora Simionescu, Nastasha A. Wijers, Joop Schaye, Jelle S. Kaastra
Summary: This paper studies the ionization effects of radiation from galaxy clusters and the cosmic background on a very tenuous plasma, and the challenge of modeling the spectral features due to photoionization. The ionization fractions obtained by considering the cosmic background as well as the distance from the emission source are discussed. The changes in column densities for different lines of sight passing close to the cluster outskirts are also predicted.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
David Spence, Massimiliano Bonamente, Jukka Nevalainen, Toni Tuominen, Jussi Ahoranta, Jelle de Plaa, Wenhao Liu, Nastasha Wijers
Summary: This paper analyzes the X-ray spectra of the quasar 1ES 1553+113 in search of absorption lines from the WHIM. The study detects a possible O vii absorption line at redshift z ~ 0.1877 with a 2.6 sigma confidence level. However, further analysis does not find evidence for additional X-ray absorbing WHIM. The paper also presents a statistical framework for cosmological inferences from absorption line analysis.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Hiroyuki Hirashita, Ting-Wen Lan
Summary: Observations of reddening in the circum-galactic medium suggest a significant presence of small grains, possibly produced through the shattering of pre-existing large grains. Physical conditions in cool clumps are favorable for small-grain production, explaining the observed reddening phenomenon.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Prakash Gaikwad, Martin G. Haehnelt, Fredrick B. Davies, Sarah E. Bosman, Margherita Molaro, Girish Kulkarni, Valentina D'Odorico, George D. Becker, Rebecca L. Davies, Fahad Nasir, James S. Bolton, Laura C. Keating, Vid Irsic, Ewald Puchwein, Yongda Zhu, Shikhar Asthana, Jinyi Yang, Samuel Lai, Anna-Christina Eilers
Summary: In this study, we measured the mean free path, photoionization rate, and neutral fraction of hydrogen at different redshifts using QSO absorption spectra. We compared our results with simulations and found significant evolution of these parameters with increasing redshift.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Rebecca L. Davies, E. Ryan-Weber, V D'Odorico, S. E. Bosman, R. A. Meyer, G. D. Becker, G. Cupani, M. Bischetti, A. M. Sebastian, A-C Eilers, E. P. Farina, F. Wang, J. Yang, Y. Zhu
Summary: This article investigates the ionization state and chemical composition of circumgalactic and intergalactic gas near the end of the reionization epoch by studying metal absorption lines in the spectra of distant quasars. With a sample of 30 luminous quasars, the authors construct a catalogue of 778 systems showing absorption in various elements, which significantly expands on existing samples and provides important insights into the early Universe.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Alexander Beckett, Simon L. Morris, Michele Fumagalli, Rich Bielby, Nicolas Tejos, Joop Schaye, Buell Jannuzi, Sebastiano Cantalupo
Summary: This study examines the distribution and dynamics of the circumgalactic and intergalactic medium around the Q0107 system, finding that high-column-density absorbers significantly impact the structure and position of galaxy absorber pairs. Star-forming galaxies are more likely to be associated with multi-sightline absorption.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
N. Tejos, S. Lopez, C. Ledoux, A. Fernandez-Figueroa, N. Rivas, K. Sharon, E. J. Johnston, M. K. Florian, G. D'Ago, A. Katsianis, F. Barrientos, T. Berg, F. Corro-Guerra, M. Hamel, C. Moya-Sierralta, S. Poudel, J. R. Rigby, M. Solimano
Summary: Gravitational-arc tomography was used to study the cool-warm enriched circumgalactic medium (CGM) of an isolated galaxy at z around 0.77. Observations revealed a direct kinematic connection between the CGM and the interstellar medium, as well as evidence for the presence of an extended disc co-rotating with the galaxy out to tens of kiloparsecs. The Mg II velocity dispersion and the modeled galaxy rotational velocity were found to be of the same order, suggesting the existence of a turbulent and pressure-supported CGM component.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Shivani Bhandari, Kasper E. Heintz, Kshitij Aggarwal, Lachlan Marnoch, Cherie K. Day, Jessica Sydnor, Sarah Burke-Spolaor, Casey J. Law, J. Xavier Prochaska, Nicolas Tejos, Keith W. Bannister, Bryan J. Butler, Adam T. Deller, R. D. Ekers, Chris Flynn, Wen-fai Fong, Clancy W. James, T. Joseph W. Lazio, Rui Luo, Elizabeth K. Mahony, Stuart D. Ryder, Elaine M. Sadler, Ryan M. Shannon, Jinlin Han, Kejia Lee, Bing Zhang
Summary: This study presents the localization and host galaxies of one repeating and two apparently nonrepeating fast radio bursts (FRBs). The results show that there are no significant differences in the host properties of repeating and apparently nonrepeating FRBs. The host galaxies of FRBs are moderately star forming and have global properties similar to core-collapse supernovae and short gamma-ray bursts hosts.
ASTRONOMICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Patricia B. Tissera, Yetli Rosas-Guevara, Emanuel Sillero, Susana E. Pedrosa, Tom Theuns, Lucas Bignone
Summary: This study analyzes the evolution of the oxygen abundance gradient of star-forming galaxies with stellar mass M-* >= 10(9)M(circle dot) in the EAGLE simulation over a redshift range of z = [0, 2.5]. The results show that the median metallicity gradient remains close to zero at all redshifts, but the scatter around the median increases with redshift. The study also finds a negative correlation between metallicity gradients and redshift for galaxies with negative gradients. The findings suggest that major mergers and gas accretion can drive strong negative or positive metallicity gradients.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
L. J. Zenocratti, M. E. De Rossi, T. Theuns, M. A. Lara-Lopez
Summary: The study using the EAGLE cosmological simulation reveals that disc galaxies have lower metallicity compared to spheroidal galaxies at a given mass, which is attributed to the fact that discs form stars at later times from low-metallicity gas and inhabit dark matter haloes with lower mass that formed later.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
James Kakos, Joel R. Primack, Aldo Rodriguez-Puebla, Nicolas Tejos, L. Y. Aaron Yung, Rachel S. Somerville
Summary: The stochastic order redshift technique (sort) is a simple and efficient method to improve cosmological redshift measurements. It uses a reference sample of high-quality redshifts to assign new redshifts to galaxies while preserving their original rank order. In this study, the sort method is tested in surveys spanning a range of redshifts and found to accurately recover the redshift-space two-point correlation function and provide improved local density estimates.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Tony Dalton, Simon L. Morris, Michele Fumagalli, Efrain Gatuzz
Summary: In this study, we estimated the properties of intergalactic medium (IGM) using quasi-stellar objects (QSOs) spectra, and found consistent results across different tracer types, providing evidence for the significant contribution of IGM to X-ray absorption in spectra.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
K. M. Rajwade, M. C. Bezuidenhout, M. Caleb, L. N. Driessen, F. Jankowski, M. Malenta, V Morello, S. Sanidas, B. W. Stappers, M. P. Surnis, E. D. Barr, W. Chen, M. Kramer, J. Wu, S. Buchner, M. Serylak, F. Combes, W. Fong, N. Gupta, P. Jagannathan, C. D. Kilpatrick, J-K Krogager, P. Noterdaeme, C. Nunez, J. Xavier Prochaska, R. Srianand, N. Tejos
Summary: This study reports on the discovery and localization of fast radio bursts (FRBs) from the MeerTRAP project in South Africa. Using a hybrid approach combining coherent and incoherent searches, three FRBs were identified and characterized. The findings provide valuable insights into the nature and origin of FRBs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Ahmed Shaban, Rongmon Bordoloi, John Chisholm, Soniya Sharma, Keren Sharon, Jane R. Rigby, Michael G. Gladders, Matthew B. Bayliss, L. Felipe Barrientos, Sebastian Lopez, Nicolas Tejos, Cedric Ledoux, Michael K. Florian
Summary: This study images the spatial extent of a cool galactic outflow using fine-structure Fe ii* emission and resonant Mg ii emission. The results show that both Fe ii* and Mg ii emissions have large spatial extents, with Mg ii emission exhibiting a patchy distribution covering approximately 13% of the total area. The study also traces Fe ii* and Mg ii emissions around three individual star-forming regions and finds that they are more spatially extended compared to the regions traced by [O ii] emission.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
C. W. James, E. M. Ghosh, J. X. Prochaska, K. W. Bannister, S. Bhandari, C. K. Day, A. T. Deller, M. Glowacki, A. C. Gordon, K. E. Heintz, L. Marnoch, S. D. Ryder, D. R. Scott, R. M. Shannon, N. Tejos
Summary: This study constrains the Hubble constant H-0 using Fast Radio Burst (FRB) observations from ASKAP and Parkes telescopes. The best-fitting value of H-0 is calculated to be 73 km s(-1) Mpc(-1). The study also explores the relationship between FRB populations and redshift and star-formation rate.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Alexander Beckettt, Simon L. Morris, Michele Fumagalli, Nicolas Tejos, Buell Jannuzi, Sebastiano Cantalupo
Summary: We use H i absorption to model potential disc and outflow structures in the circumgalactic medium, and find possible outflows and co-rotating structures, suggesting that geometric cuts are not sufficient to distinguish between discs and outflows in single line-of-sight studies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Fernandez-Figueroa, S. Lopez, N. Tejos, T. A. M. Berg, C. Ledoux, P. Noterdaeme, A. Afruni, L. F. Barrientos, J. Gonzalez-Lopez, M. Hamel, E. J. Johnston, A. Katsianis, K. Sharon, M. Solimano
Summary: This study uses spatially resolved spectroscopy of a distant giant gravitational arc to investigate orientation effects on Mg ii absorption and covering fraction in the circumgalactic medium. The results reveal a non-isotropic gas distribution and suggest the presence of bipolar metal-rich winds.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Ken Mawatari, Akio K. K. Inoue, Toru Yamada, Tomoki Hayashino, J. Xavier Prochaska, Khee-Gan Lee, Nicolas Tejos, Nobunari Kashikawa, Takuya Otsuka, Satoshi Yamanaka, David J. J. Schlegel, Yuichi Matsuda, Joseph F. F. Hennawi, Ikuru Iwata, Hideki Umehata, Shiro Mukae, Masami Ouchi, Yuma Sugahara, Yoichi Tamura
Summary: We conducted a deep spectroscopic survey using the DEIMOS instrument on the Keck telescope to map high-z H i gas in the SSA22 field through Ly alpha absorption analysis. We confirmed the spectra of 198 galaxies in the 26 x 15 arcmin(2) area, with a redshift range of 2.5 < z < 6, including 148 newly determined galaxies. Our compiled catalog of 730 galaxies at z > 2 in the SSA22 field is comparable to other major extragalactic survey fields. Our data set allows us to create a tomographic map of H i gas at z greater than or similar to 3.
ASTRONOMICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Alexander Beckett, Simon L. Morris, Michele Fumagalli, Nicolas Tejos, Buell Jannuzi, Sebastiano Cantalupo
Summary: We test simple disc and outflow models against the observations of H i gas within a few virial radii of galaxies in pairs and groups. Our models can reproduce approximately 75% of the identified absorption components within 500 km/s of a group galaxy, suggesting that most of the H i around groups is consistent with the circumgalactic medium (CGM) of individual galaxies. Gas stripped in interactions between galaxies may explain some of the remaining absorption, but further evidence is needed. H i column densities and detections of O vi are higher around groups compared to isolated galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)