Strong Mg II and Fe II Absorbers at 2.2 < z < 6.0

Abstract

We present a study of strong intervening absorption systems in the near-IR spectra of 31 luminous quasars at $z>5.7$. The quasar spectra were obtained with {\it Gemini} GNIRS that provide continuous wavelength coverage from $\sim$0.9 to $\sim$2.5 $\mu$m. We detect 32 strong Mg II doublet absorbers with rest-frame equivalent width $W_r$ ($\lambda 2796$) $>1.0$ Åat $2.2<z<6.0$. Each Mg II absorber is confirmed by at least two associated Fe II absorption lines in the rest-frame wavelength range of $\sim 1600-2600$ Å. We find that the comoving line density ($dN/dX$) of the strong Fe II-bearing Mg II absorbers decreases towards higher redshift at $z>3$, consistent with previous studies. Compared with strong Mg II absorbers detected in damped Ly$\alpha$ systems at 2 $<z<$ 4, our absorbers are potentially less saturated and show much larger rest-frame velocity widths. This suggests that the gas traced by our absorbers are potentially affected by galactic superwinds. We analyze the {\it Hubble Space Telescope} near-IR images of the quasars and identify possible associated galaxies for our strong absorbers. There are a maximum of two galaxy candidates found within 5" radius of each absorber. The median F105W-band magnitude of these galaxy candidates is 24.8 mag, which is fainter than the $L^{\ast }$ galaxy luminosity at $z\sim$ 4. By using our observed $dN/dX$ of strong Mg II absorbers and galaxy candidates median luminosity, we suggest that at high redshift, strong Mg II absorbers tend to have a more disturbed environment but smaller halo size than that at $z<$ 1.

arXiv comment16 pages, 12 figures, 4 tables. Accepted for publication in ApJ

References in corpus (49)

• Overview of the DESI Legacy Imaging Surveys
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• The Circumgalactic Medium
• UV-continuum slopes at z~4-7 from the HUDF09+ERS+CANDELS observations: Discovery of a well-defined UV-color magnitude relationship for z>=4 star-forming galaxies
• Damped Lyman Alpha Systems at z<1.65: The Expanded SDSS HST Sample
• The Final SDSS High-Redshift Quasar Sample of 52 Quasars at z>5.7
• An Empirical Characterization of Extended Cool Gas Around Galaxies Using MgII Absorption Features
• Signatures of Cool Gas Fueling a Star-Forming Galaxy at Redshift 2.3
• The Kinematic Connection Between QSO-Absorbing Gas and Galaxies at Intermediate Redshift
• Mg II Absorption Systems in SDSS QSO Spectra
• Gemini GNIRS near-infrared spectroscopy of 50 quasars at z>~5.7
• The JHU-SDSS metal absorption line catalog: redshift evolution and properties of Mg II absorbers
• The Direct Detection of Cool, Metal-Enriched Gas Accretion onto Galaxies at z ~ 0.5
• MAGIICAT II. General Characteristics of the MgII Absorbing Circumgalactic Medium
• New perspectives on strong z=0.5 MgII absorbers: are halo-mass and equivalent width anti-correlated?
• Halo Gas Cross Sections And Covering Fractions of MgII Absorption Selected Galaxies
• A Direct Measurement of the IGM Opacity to HI Ionizing Photons
• QSO Absorbing Galaxies at z<~1: Deep Imaging and Spectroscopy in the Field of 3C 336
• On the Incidence and Kinematics of Strong Mg II Absorbers
• MusE GAs FLOw and Wind (MEGAFLOW) II. A study of gas accretion around $z\approx 1$ star-forming galaxies with background quasars
• A translucent interstellar cloud at z=2.69: CO, H2 and HD in the line-of-sight to SDSS J123714.60+064759.5
• Optical properties and spatial distribution of MgII absorbers from SDSS image stacking
• Physical Conditions in the Low-Ionization Component of Starburst Outflows: The Shape of Near-Ultraviolet and Optical Absorption-Line Troughs in Keck Spectra of ULIRGs
• MusE GAs FLOw and Wind (MEGAFLOW) III: galactic wind properties using background quasars
• Remarks on statistical errors in equivalent widths
• MAGIICAT I. The MgII Absorber-Galaxy Catalog
• Morphological Properties of z~0.5 Absorption-Selected Galaxies: The Role of Galaxy Inclination
• Probing star formation across cosmic time with absorption line systems
• MusE GAs FLOw and Wind (MEGAFLOW) I: First MUSE results on background quasars
• Cosmic dust in MgII absorbers
• High-Redshift Superwinds as the Source of the Strongest Mg II Absorbers: A Feasibility Analysis
• The properties of the cool circumgalactic gas probed with the SDSS, WISE and GALEX surveys
• A Survey of MgII Absorption at 2 < z < 6 with Magellan / FIRE: I: Sample and Evolution of the MgII Frequency
• The Nuclear Near-Infrared Spectral Properties of Nearby Galaxies
• The z=0.8596 Damped Lyman Alpha Absorbing Galaxy Toward PKS 0454+039
• The Pittsburgh Sloan Digital Sky Survey MgII Quasar Absorption-Line Survey Catalog
• MAGIICAT VI. The MgII Intragroup Medium is Kinematically Complex
• Mg II Absorption at 2<z<7 with Magellan/FIRE, III. Full Statistics of Absorption Towards 100 High-Redshift QSOs
• Ultra-strong MgII Absorbers as a Signature of Cool Intragroup Gas
• The Co-Evolution of Galaxies and the Cool Circumgalactic Medium Probed with the SDSS and DESI Legacy Imaging Surveys
• The Environments of Ultra-strong Mg II Absorbers
• Galaxy counterparts of intervening high-z sub-DLAs/DLAs and MgII absorbers towards gamma-ray bursts
• Near Infrared spectroscopic observations of high redshift C~{\sc i} absorbers
• Observations of Mg II Absorption Near z ~ 1 Galaxies Selected From The DEEP2 Redshift Survey
• The comoving mass density of MgII from $z\sim 2$ to $5.5$
• VoigtFit: A Python package for Voigt profile fitting
• On the selection of damped Lyman alpha systems using MgII absorption at 2<z<4
• The Ly$\alpha$ emission from high-$z$ galaxies hosting strong Damped Ly$\alpha$ systems
• Evolution of the Population of Very Strong MgII Absorbers

Cited by in corpus (12)

• XQR-30: the ultimate XSHOOTER quasar sample at the reionization epoch
• The XQR-30 Metal Absorber Catalog: 778 Absorption Systems Spanning 2 < z < 6.5
• Metallicity in Quasar Broad Line Regions at Redshift $\sim$ 6
• Detecting and Characterizing Mg II absorption in DESI Survey Validation Quasar Spectra
• Metal enrichment and evolution in four z > 6.5 quasar sightlines observed with JWST/NIRSpec
• Examining the Decline in the C IV Content of the Universe over 4.3 < z < 6.3 using the E-XQR-30 Sample
• A SPectroscopic survey of biased halos In the Reionization Era (ASPIRE): JWST Discovers an Overdensity around a Metal Absorption-selected Galaxy at $z\sim 5.5$
• Modeling the Spectral Diversity of Quasars in the Sixteenth Data Release from the Sloan Digital Sky Survey
• Spectral variability studies in Active Galactic Nuclei: Exploring continuum and emission line regions in the age of LSST and JWST
• Searching for [CII] Emission from the First Sample of $z\sim 6$ OI Absorption-Associated Galaxies with ALMA
• Automated quasar continuum estimation using neural networks: a comparative study of deep-learning architectures
• Interstellar and Circumgalactic Properties of an Unseen $z=6.84$ Galaxy: Abundances, Ionization, and Heating in the Earliest Known Quasar Absorber