DISCOVERY OF A LARGE-SCALE GALAXY FILAMENT NEAR A CANDIDATE INTERGALACTIC X-RAY ABSORPTION SYSTEM

Journal Article · Sat Nov 20 04:00:00 EST 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/724/1/L25· OSTI ID:21452672

Williams, Rik J; Mulchaey, John S; Kollmeier, Juna A

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 sight line. Using the Sloan Digital Sky Survey (SDSS), 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 a 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 an {approx}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 a large-scale galaxy structure and a blind X-ray WHIM detection.

• OSTI ID: 21452672
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 1 Vol. 724; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABSORPTION
COSMOLOGY
DISTRIBUTION
ELECTROMAGNETIC RADIATION
GALAXIES
IONIZING RADIATIONS
PROBABILITY
RADIATIONS
RANDOMNESS
RED SHIFT
SIMULATION
SORPTION
UNIVERSE
X RADIATION