On the nature of the z=0 X-ray absorbers: I. Clues from an external group

Abstract

Absorption lines of OVII at redshift zero are observed in high quality Chandra spectra of extragalactic sightlines. The location of the absorber producing these lines, whether from the corona of the Galaxy or from the Local Group or even larger scale structure, has been a matter of debate. Here we study another poor group like our Local Group to understand the distribution of column density from galaxy to group scales. We show that we cannot yet rule out the group origin of z=0 systems. We further argue that the debate over Galactic vs. extragalactic origin of z=0 systems is premature as they likely contain both components and predict that future higher resolution observations will resolve the z=0 systems into multiple components.

Submitted to ApJL

References in corpus (5)

• The Search for the Missing Baryons at Low Redshift
• X-Ray Absorption from the Milky Way Halo and the Local Group
• 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
• Warm-Hot Intergalactic Medium Associated with the Coma Cluster

Cited by in corpus (4)

• Probing the Anisotropy of the Milky Way Gaseous Halo-II: sightline toward Mrk509
• Virial clouds explaining the observed rotational asymmetry in the galactic halos
• Seeing the halo rotation of nearby spiral galaxies using Planck data
• On the nature of the z=0 X-ray absorbers: II. The contrast between local and AGN host galaxy absorption