Constraining the Size of the Circumgalactic Medium Using the Transverse Autocorrelation Function of C IV Absorbers in Paired Quasar Spectra

Abstract

The circumgalactic medium (CGM) plays a vital role in the formation and evolution of galaxies, acting as a lifeline between galaxies and the surrounding intergalactic medium (IGM). In this study we leverage a unique sample of quasar pairs to investigate the properties of the CGM with absorption line tomography. We present a new sample of medium resolution Keck/ESI, Magellan/MagE, and VLT/XSHOOTER spectra of 29 quasar pairs at redshift $2<z<3$. We supplement the sample with additional spectra of 32 pairs from the literature, creating a catalog of 61 quasar pairs with angular separations between 1.7" and 132.9" and projected physical separations ($r_{\perp }$) between 14 kpc and 887 kpc. We construct a catalog of 906 metal-line absorption doublets of C IV ($\lambda \lambda 1548,1550$) with equivalent widths ranging from 6 mÅ $\le W_{r,1550}\le 2053$ mÅ. The best fit linear model to the log-space equivalent width frequency distribution ($\log f(W_r)=m\log (W_r)+b$) of the sample yields coefficients of $m=-1.44\pm 0.16$ and $b=-0.43\pm 0.16$. To constrain the projected extent of C IV, we calculate the transverse autocorrelation function. The flattening of the autocorrelation function at low $r_{\perp }$ provides a lower limit for the coherence length of the metal enriched CGM - on the order of 200 $h^{-1}$ comoving kpc. This physical size constraint allows us to refine our understanding of the metals in the CGM, where the extent of C IV in the CGM depends on gas flows, feedback, timescale of metal injection and mixing, and the mass of the host galaxies.

19 pages, 8 figures, 2 tables, Accepted for publication by The Astronomical Journal

References in corpus (22)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• The Circumgalactic Medium
• A census of baryons in the Universe from localized fast radio bursts
• The COS-Halos Survey: Physical Conditions and Baryonic Mass in the Low-Redshift Circumgalactic Medium
• Metallicity Evolution of Damped Lyman-alpha Systems out to z~5
• The Cosmic Baryon and Metal Cycles
• The COS-Dwarfs Survey: The Carbon Reservoir Around sub-L* Galaxies
• The MagE Spectrograph
• The First Positive Detection of Molecular Gas in a GRB Host Galaxy
• Quasars Probing Quasars II: The Anisotropic Clustering of Optically Thick Absorbers around Quasars
• Transverse Sizes of CIV Absorption Systems Measured from Multiple QSO Sightlines
• Unveiling the Secrets of Metallicity and Massive Star Formation Using DLAs along Gamma-ray Bursts
• Characterizing the Low-Redshift Intergalactic Medium towards PKS1302-102
• MUSE Analysis of Gas around Galaxies (MAGG) -- I: Survey design and the environment of a near pristine gas cloud at z~3.5
• Witnessing galaxy assembly in an extended z~3 structure
• Metal-enriched halo gas across galaxy overdensities over the last 10 billion years
• Tomography of the intergalactic medium with Ly-alpha forests in close QSO pairs
• MusE GAs Flow and Wind (MEGAFLOW) VI. A study of CIV and MgII absorbing gas surrounding [OII] emitting galaxies
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: The Damped Lyman-$\alpha$ systems Catalog
• ALMA [CII] 158um imaging of an HI-Selected Major Merger at z~4
• Absorption-selected galaxies trace the low-mass, late-type, star-forming population at $z\sim 2-3$
• The nature of H{\sc i}-absorption-selected galaxies at $z\approx 4$