DEEP CHANDRA OBSERVATIONS OF HCG 16. II. THE DEVELOPMENT OF THE INTRA-GROUP MEDIUM IN A SPIRAL-RICH GROUP

作者：O' Sullivan E^*; Vrtilek J M; David L P; Giacintucci S; Zezas A; Ponman T J; Mamon G A; Nulsen P; Raychaudhury S

来源：Astrophysical Journal, 2014, 793(2): 74.

DOI：10.1088/0004-637X/793/2/74

• galaxies: clusters: intracluster medium
• galaxies: groups: individual (HCG 16)
• galaxies: individual (NGC 838, NGC 839)
• galaxies: starburst
• X-rays: galaxies

We use a combination of deep Chandra X-ray observations and radio continuum imaging to investigate the origin and current state of the intra-group medium (IGM) in the spiral-rich compact group HCG 16. We confirm the presence of a faint (L-X,L-bolo = 1.87(-0.66)(+1.03) x 10(41) erg s(-1)), low-temperature (0.30(-0.05)(+0.07) keV) IGM extending throughout the ACIS-S3 field of view, with a ridge linking the four original group members and extending to the southeast, as suggested by previous ROSAT and XMM-Newton observations. This ridge contains 6.6(-3.3)(+3.9) x 10(9) M-circle dot of hot gas and is at least partly coincident with a large-scale H I tidal filament, indicating that the IGM in the inner part of the group is highly multi-phase. We present evidence that the group is not yet virialized, and show that gas has probably been transported from the starburst winds of NGC 838 and NGC 839 into the surrounding IGM. Considering the possible origin of the IGM, we argue that material ejected by galactic winds may have played a significant role, contributing 20%-40% of the observed hot gas in the system.

• 出版日期2014-10-1