Results 81 to 90 of about 1,317 (190)

One H2 molecule per ten million H atoms reveals sub-parsec-scale cold overdensities at z ∼ 4★

Astronomy & Astrophysics
We present the detection and analysis of H2 absorption at z = 4.24 towards the bright quasar J 0007−5705, which was observed with the Very Large Telescope as part of the ESPRESSO QUasar Absorption Line Survey (EQUALS). The high resolving power of R ≈ 120 
Noterdaeme P., Balashev S., Berg T., Cristiani S., Cuellar R., Cupani G., Di Stefano S., D’Odorico V., Fian C., Godard B., López S., Milaković D., Trost A., Welsh L.   +13 more
doaj   +1 more source

Highly Ionized Gas in the Zone of Avoidance: Using the CIViL⋆ Survey to Pinpoint Physical Conditions of Gaseous Halos

The Astrophysical Journal
This paper investigates the physical conditions of the circumgalactic medium of L ^⋆ galaxies through explorations of observed ion tracer gas kinematics and comparisons of observations to different ionization models.
Samantha L. Garza, Yakov Faerman, Trystyn A. M. Berg, Jessica K. Werk, Benjamin D. Oppenheimer, Rongmon Bordoloi, Sara Ellison   +6 more
doaj   +1 more source

Galaxy–Absorber Association in the Epoch of Reionization: Galactic Population Luminosity Distribution for Different Absorbers at 10 ≥ z ≥ 5.5

The Astrophysical Journal
How do galaxies of different luminosities contribute to the metal absorber populations of varying species and strength? We present our analysis of the predicted metal contributions from galaxies as observed in quasar absorption line spectra during the ...
Samir Kušmić, Kristian Finlator, Ezra Huscher, Maya Steen   +3 more
doaj   +1 more source

Circumnuclear Gas of a Quasar in Absorption and Emission Lines

The Astrophysical Journal
We present a detailed analysis of the unusual absorption- and emission-line spectrum of the quasar SDSS J074850.39+442439.0 (hereafter J0748+4424) at a redshift of z = 2.18. The archival SDSS optical spectrum is abundant in narrow absorption lines (NALs)
Xuejie Dai, Lei Hao, Peng Jiang, Zhenzhen Li, Xiheng Shi, Shengmiao Wu, Yanfei Zou, Yipeng Zhou, Tuo Ji, Qiguo Tian, Bo Liu, Lin Lin, Hongyan Zhou   +12 more
doaj   +1 more source

The Distance to the Magellanic Stream: Constraints from Optical Absorption along Stellar Sight Lines

The Astrophysical Journal
The Magellanic Stream is a large tail of neutral and ionized gas originating from tidal and hydrodynamical interactions between the Magellanic Clouds as they orbit the Milky Way (MW).
Sapna Mishra, Andrew J. Fox, J. V. Smoker, Scott Lucchini, Elena D’Onghia   +4 more
doaj   +1 more source

Circum-Galactic Medium in the Halo of Quasars

Frontiers in Astronomy and Space Sciences, 2017
The properties of circum-galactic gas in the halo of quasar host galaxies are investigated analyzing Mg II 2800 and C IV 1540 absorption-line systems along the line of sight close to quasars.
Riccardo Ottolina, Renato Falomo, Aldo Treves, Michela Uslenghi, Jari K. Kotilainen, Riccardo Scarpa, Emanuele Paolo Farina   +6 more
doaj   +1 more source

The Mass Density of Mg ii Absorbers from the Australian Dark Energy Survey

The Astrophysical Journal
We present an all-southern sky survey for Mg ii λλ 2796, 2803 doublet absorbers in 951 z < 4 active galactic nucleus/quasar spectra from the Australian Dark Energy Survey.
Asif Abbas, Christopher W. Churchill, Glenn G. Kacprzak, Christopher Lidman, Susanna Guatelli, Sabine Bellstedt   +5 more
doaj   +1 more source

Investigating Ionization in the Intergalactic Medium

The Astrophysical Journal
The intergalactic medium (IGM) contains >50% of the baryonic mass of the Universe, yet the mechanisms responsible for keeping the IGM ionized have not been fully explained.
Brad Koplitz, Anjali Ramesh, Sanchayeeta Borthakur   +2 more
doaj   +1 more source

UEG Week 2025 Oral Presentations

United European Gastroenterology Journal, Volume 13, Issue S8, Page S7-S188, October 2025.
wiley   +1 more source

Probing the He ii Reionization ERA via Absorbing C iv Historical Yield (HIERACHY). III. The C iv Absorber Catalog and Initial Results on Cosmic Abundance Evolution at z ≈ 3–5

The Astrophysical Journal
As part of the HIERACHY program, we collect the high signal-to-noise ratio and high-spectral resolution optical spectra of 25 quasars at z  ≈ 4–5 to constrain the C iv evolution at z  ≈ 3–5.
Xiaodi Yu, Zhijie Qu, Zheng Cai, Jiang-Tao Li, Huiyang Mao, Xin Wang   +5 more
doaj   +1 more source