Results 51 to 60 of about 335 (139)

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

Metal-strong Inflows at the Outer-galactic-scale of a Quasar

The Astrophysical Journal
We present an analysis of the absorption-line system in the Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph spectrum at a redshift of z _a = 3.1448 associated with the quasar SDSS J122040.23+092326.96, whose systematic redshift is z _e =
Qiguo Tian, Lei Hao, Yipeng Zhou, Xiheng Shi, Tuo Ji, Peng Jiang, Lin Lin, Zhenya Zheng, Hongyan Zhou   +8 more
doaj   +1 more source

Measuring the Mean Free Path of H i Ionizing Photons at 3.2 ≤ z ≤ 4.6 with DESI Y1 Quasars

The Astrophysical Journal Letters
The mean free path of ionizing photons in the intergalactic medium (IGM; ${\lambda }_{{\rm{mfp}}}^{912}$ ) is a crucial quantity in modeling the ionization state of the IGM and the extragalactic ultraviolet background, and it is widely used in ...
Anning Gao, J. Xavier Prochaska, Zheng Cai, Siwei Zou, Cheng Zhao, Zechang Sun, S. Ahlen, D. Bianchi, D. Brooks, T. Claybaugh, A. de la Macorra, Arjun Dey, P. Doel, J. E. Forero-Romero, E. Gaztañaga, S. Gontcho A Gontcho, G. Gutierrez, K. Honscheid, S. Juneau, A. Kremin, P. Martini, A. Meisner, R. Miquel, J. Moustakas, A. Muñoz-Gutiérrez, J. A. Newman, I. Pérez-Ràfols, G. Rossi, E. Sanchez, M. Schubnell, D. Sprayberry, G. Tarlé, B. A. Weaver, H. Zou   +33 more
doaj   +1 more source

The Cosmic Ultraviolet Baryon Survey (CUBS). VII. On the Warm-hot Circumgalactic Medium Probed by O vi and Ne viii at 0.4 ≲ z ≲ 0.7

The Astrophysical Journal
This paper presents a newly established sample of 103 unique galaxies or galaxy groups at 0.4 ≲ z ≲ 0.7 from the Cosmic Ultraviolet Baryon Survey (CUBS) for studying the warm-hot circumgalactic medium (CGM) probed by both O vi and Ne viii absorption. The
Zhijie Qu, Hsiao-Wen Chen, Sean D. Johnson, Gwen C. Rudie, Fakhri S. Zahedy, David DePalma, Joop Schaye, Erin T. Boettcher, Sebastiano Cantalupo, Mandy C. Chen, Claude-André Faucher-Giguère, Jennifer I-Hsiu Li, John S. Mulchaey, Patrick Petitjean, Marc Rafelski   +14 more
doaj   +1 more source

Probing the Coherence of Metal Absorbers toward Background Quasar Pairs

The Astrophysical Journal
We investigate the spatial coherence of metal absorption lines in the circumgalactic medium using 4115 quasar pairs from Sloan Digital Sky Survey DR16. We identify 184 Mg ii (15 with dual detections) and 50 C iv (11 with dual detections) absorber pairs ...
Jing Li, Rui-Jing Lu, Wei-Rong Huang
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

EIGER IV. The Cool 104 K Circumgalactic Environment of High-redshift Galaxies Reveals Remarkably Efficient Intergalactic Medium Enrichment

The Astrophysical Journal
We report new observations of the cool diffuse gas around 29, 2.3 < z < 6.3 galaxies using deep JWST/NIRCam slitless grism spectroscopy around the sight line to the quasar J0100+2802. The galaxies span a stellar mass range of $7.1\leqslant {\rm{log}}{M}_{
Rongmon Bordoloi, Robert A. Simcoe, Jorryt Matthee, Daichi Kashino, Ruari Mackenzie, Simon J. Lilly, Anna-Christina Eilers, Bin Liu, David DePalma, Minghao Yue, Rohan P. Naidu   +10 more
doaj   +1 more source

Subaru high-resolution spectroscopy of complex metal absorption lines of the quasar HS 1603+3820

Subaru high-resolution spectroscopy of complex metal absorption lines of the quasar HS 1603+3820
We present a high-resolution spectrum of the quasar HS 1603+ 3820 (z(em) = 2.542), observed with the High Dispersion Spectrograph on the Subaru Telescope. This quasar, first discovered in the Hamburg/CfA Quasar Survey, has 11 C IV lines at 1.96 < z(abs) < 2.55.
openaire   +1 more source

Mapping a Quasar Outflow from Parsec to Kiloparsec Scales: A Combined HST Absorption and VLT Emission Investigation

The Astrophysical Journal
Linking nuclear winds to galactic-scale outflows remains a major observational challenge in understanding the multiscale physics of active galactic nucleus feedback.
Mayank Sharma, Travis C. Fischer, Manuela Bischetti, Nahum Arav, Fabrizio Fiore, Chiara Feruglio, Manoj Ghosh   +6 more
doaj   +1 more source