Discovery of a large-scale galaxy filament near a candidate intergalactic X-ray absorption system

Abstract

We present an analysis of the large-scale galaxy distribution around two possible warm-hot intergalactic medium (WHIM) absorption systems reported along the Markarian 421 sightline. Using the Sloan Digital Sky Survey, we find a prominent galaxy filament at the redshift of the z=0.027 X-ray absorption line system. The filament exhibits a width of 3.2 Mpc and length of at least 20 Mpc, comparable to the size of WHIM filaments seen in cosmological simulations. No individual galaxies fall within 350 projected kpc so it is unlikely that the absorption is associated with gas in a galaxy halo or outflow. Another, lower-significance X-ray absorption system was reported in the same Chandra spectrum at z=0.011, but the large-scale structure in its vicinity is far weaker and may be a spurious alignment. By searching for similar galaxy structures in 140 random smoothed SDSS fields, we estimate a ~5-10% probability of the z=0.027 absorber-filament alignment occurring by chance. If these two systems are indeed physically associated, this would represent the first known coincidence between large-scale galaxy structure and a blind X-ray WHIM detection.

arXiv commentAccepted to ApJ Letters. 8 pages emulateapj, 4 figures, minor changes in response to referee report

References in corpus (25)

• The Sloan Digital Sky Survey: Technical Summary
• The Seventh Data Release of the Sloan Digital Sky Survey
• Spectroscopic Target Selection in the Sloan Digital Sky Survey: The Main Galaxy Sample
• Galaxy Zoo : Morphologies derived from visual inspection of galaxies from the Sloan Digital Sky Survey
• The Galaxy Luminosity Function and Luminosity Density at Redshift z=0.1
• Where are the Baryons?
• Baryons in the Warm-Hot Intergalactic Medium
• Do Hot Haloes Around Galaxies Contain the Missing Baryons?
• Detection of hot gas in the filament connecting the clusters of galaxies Abell 222 and Abell 223
• Chandra Detection of the First X-ray Forest along the Line of Sight To Mkn 421
• Chandra Detection of OVIII Ly-alpha Absorption from an Overdense Region in the Intergalactic Medium
• The intergalactic medium over the last 10 billion years I: Lyman alpha absorption and physical conditions
• X-Ray Absorption By WHIM in the Sculptor Wall
• Confirmation of X-Ray Absorption by WHIM in the Sculptor Wall
• The O VII X-ray forest toward Markarian 421: Consistency between XMM-Newton and Chandra
• On the Putative Detection of z>0 X-ray Absorption Features in the Spectrum of Markarian 421
• Probing the Local Group Medium Toward Mkn 421 with Chandra and FUSE
• Studying the WHIM Content of the Galaxy Large-Scale Structures along the Line of Sight to H 2356-309
• Confirming the Detection of an Intergalactic X-ray Absorber Toward PKS 2155-304
• Chandra and Far Ultraviolet Spectroscopic Explorer Observations of z~0 Warm-Hot Gas Toward PKS 2155-304
• Evidence for the Missing Baryons in the Angular Correlation of the Diffuse X-ray Background
• Warm-Hot Intergalactic Medium in the Sculptor Supercluster
• XMM-Newton View of the z>0 Warm-Hot Intergalactic Medium Toward Markarian 421
• Crawling the Cosmic Network: Exploring the Morphology of Structure in the Galaxy Distribution
• A galaxy overdensity at z=0.401 associated with an X-ray emitting structure of Warm-Hot Intergalactic Medium

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• The Properties of Low Redshift Intergalactic O VI Absorbers Determined from High S/N Observations of 14 QSOs with the Cosmic Origins Spectrograph
• Growing a `Cosmic Beast': Observations and Simulations of MACS J0717.5+3745
• Chandra View of the Warm-Hot IGM toward 1ES 1553+113: Absorption Line Detections and Identifications (Paper I)
• Detecting the warm-hot intergalactic medium through X-ray absorption lines
• Warm-hot gas in groups and galaxies toward H2356-309
• Expected properties of the Two-Point Autocorrelation Function of the IGM
• An X-ray WHIM metal absorber from a Mpc-scale empty region of space
• Thermal and Chemical Evolution of Collapsing Filaments
• SUZAKU Observation of a New Merging Group of Galaxies at a Filamentary Junction
• Spectroscopically Identified Emission Line Galaxy Pairs in the WISP survey
• Exploring Hot Gas at Junctions of Galaxy Filaments with Suzaku
• Future Detections of the Warm-Hot Intergalactic Medium using Bright Power Law Sources with NewAthena