CAVITIES AND SHOCKS IN THE GALAXY GROUP HCG 62 AS REVEALED BY CHANDRA, XMM-NEWTON, AND GIANT METREWAVE RADIO TELESCOPE DATA

Journal Article · Sat May 01 00:00:00 EDT 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/714/1/758· OSTI ID:21448887

Gitti, Myriam; O'Sullivan, Ewan; Giacintucci, Simona; David, Laurence P; Vrtilek, Jan; Nulsen, Paul E. J. ^[1]; Raychaudhury, Somak ^[2]

---

1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
2. University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

We report on the results of an analysis of Chandra, XMM-Newton, and new Giant Metrewave Radio Telescope (GMRT) data of the X-ray bright compact group of galaxies HCG 62, which is one of the few groups known to possess clear, small X-ray cavities in the inner regions. This is part of an ongoing X-ray/low-frequency radio study of 18 groups, initially chosen for the availability of good-quality X-ray data and evidence for active galactic nucleus/hot gas interaction. At higher frequency (1.4 GHz), the HCG 62 cavity system shows minimal if any radio emission, but the new GMRT observations at 235 MHz and 610 MHz clearly detect extended low-frequency emission from radio lobes corresponding to the cavities. By means of the synergy of X-ray and low-frequency radio observations, we compare and discuss the morphology, luminosity, and pressure of the gas and of the radio source. We find that the radio source is radiatively inefficient, with a ratio of radio luminosity to mechanical cavity power of {approx}10{sup -4}, and that the radio pressure of the lobes is about 1 order of magnitude lower than the X-ray pressure of the surrounding thermal gas. Thanks to the high spatial resolution of the Chandra surface brightness and temperature profiles, we also identify a shock front located at 36 kpc to the southwest of the group center, close to the southern radio lobe, with a Mach number {approx}1.5 and a total power which is about 1 order of magnitude higher than the cavity power. Such a shock may have heated the gas in the southern region, as indicated by the temperature map. The shock may also explain the arc-like region of enriched gas seen in the iron abundance map, as this may be produced by a non-Maxwellian electron distribution near its front.

• OSTI ID: 21448887
• Journal Information: Astrophysical Journal, Vol. 714, Issue 1; Other Information: DOI: 10.1088/0004-637X/714/1/758; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABUNDANCE
BRIGHTNESS
ELECTRONS
EMISSION
GALAXY CLUSTERS
IRON
LUMINOSITY
MACH NUMBER
RADIO TELESCOPES
SPATIAL RESOLUTION
X-RAY GALAXIES
ANTENNAS
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
DIMENSIONLESS NUMBERS
ELECTRICAL EQUIPMENT
ELECTRONIC EQUIPMENT
ELEMENTARY PARTICLES
ELEMENTS
EQUIPMENT
FERMIONS
GALAXIES
LEPTONS
METALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIO EQUIPMENT
RESOLUTION
TELESCOPES
TRANSITION ELEMENTS
VELOCITY