X-Ray Constraints on the Hot Gaseous Corona of Edge-on Late-type Galaxies in Virgo

Abstract

We present a systematic study of the putative hot gas corona around late-type galaxies (LTGs) residing in the Virgo cluster, based on archival Chandra observations. Our sample consists of 21 nearly edge-on galaxies representing a range of star formation rate (SFR) of 0.2–3 M _⊙ yr ^−1 and a range of stellar mass ( M _* ) of (0.2–10) × 10 ^10 M _⊙ , the majority of which have not been explored with high-sensitivity X-ray observations so far. Significant extraplanar diffuse X-ray (0.5–2 keV) emission is detected in only three LTGs, which are also the three galaxies with the highest SFR. A stacking analysis is performed for the remaining galaxies without individual detection, dividing the whole sample into two subsets based on SFR, stellar mass, or specific SFR. Only the high-SFR bin yields a significant detection, which has a value of L _X ∼ 3 × 10 ^38 erg s ^−1 per galaxy. The stacked extraplanar X-ray signals of the Virgo LTGs are consistent with the empirical L _X –SFR and L _X – M _* relations found among highly inclined disk galaxies in the field, but appear to be systematically lower than those of a comparison sample of simulated star-forming galaxies in clusters identified from the Illustris-TNG100 simulation. The apparent paucity of hot gas coronae in the sampled Virgo LTGs might be understood as the net outcome of the long-lasting effect of ram pressure stripping exerted by the hot intracluster medium and in-disk star-forming activity acting on shorter timescales. A better understanding of the roles of environmental effects in regulating the hot gas content of cluster galaxies invites sensitive X-ray observations for a large sample of galaxies.

Keywords

• Virgo Cluster
• X-ray astronomy
• Late-type galaxies
• Disk galaxies
• Circumgalactic medium