Mapping the dark matter in the NGC 5044 group with ROSAT: Evidence for a nearly homogeneous cooling flow with a cooling wake

• DOI: 10.1086/174264
• Publication Date: 2002-07-26T18:37:00Z
• Authors: Laurence P. David; Christine Jones; William Forman; Stuart Daines
• Keywords: ROSAT; Cooling flow; Cold dark matter

view Abstract Citations (124) References (63) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Mapping the Dark Matter in NGC 5044 Group with ROSAT: Evidence for a Nearly Homogeneous Cooling Flow Wake David, Laurence P. ; Jones, Christine Forman, William Daines, Stuart The group of galaxies was observed by ROSAT PSPC 30 ks during its reduced pointed phase (1991 July). Due to relatively cool gas temperature (kT = 0.98+/-0.02 keV) and excellent photon statistics (65,000 net counts), we are able determine precisely number fundamental properties within 250 kpc central galaxy. In particular, present model-independent measurements total gravitating mass, abundance profiles gas, mass accretion rate. Between 60 kpc, is nearly isothermal T proportional r^-0.13+/-0.03. can be unambiguously determined from density using equation hydrostatic equilibrium. Within 1.6 x 10^13^ M_sun_, yielding mass-to-light ratio 130 M_sun_/L_sun_. baryons (gas stars) comprise 12% this radius. At small radii, clearly increases outward attains maximum value at kpc. positive gradient center confirms existence cooling flow, flow region extends well beyond radius between 100 150 There two distinct regions separated maximum. outer region, uniform Fe approximately 80% solar, homogeneous M 20-25 M_sun_ yr^-1^, X-ray contours spherically symmetric, ρ_gas_ r^-1.6^ inner profile has gradient, rate decreases rapidly inward, steeper, X- ray image shows some substructure. offset centroid indicating that galaxy may have residual velocity respect potential. also linear feature an extent one end coincident 5044. emission softer than ambient gas. We interpret as "cooling wake" formed accreting it gravitationally focused into wake One most surprising results our observation discovery flow. Prior concerning flows indicate r. This relation implies significant deposition occurs large radii which generates inhomogeneous essentially constant 40 (well radius). Significant (a declining M) does not commence until accretes where radiative time ~10^9^ yr. corresponds maximum, break profile, onset structure image. A Hubble H_0_ 50 km s^-1^ Mpc^-1^ used throughout paper. Publication: Astrophysical Journal Pub Date: June 1994 DOI: 10.1086/174264 Bibcode: 1994ApJ...428..544D Keywords: Abundance; Flows (Astrophysics); Matter; Galactic Clusters; Mass; Gravitational Fields; Intergalactic Media; Iron; Mapping; Temperature Profiles; Contours; Position Sensing; Rosat Mission; Spatial Resolution; Spectral X Ray Imagery; Rays; Astronomy; GALAXIES: COOLING FLOWS; COSMOLOGY: DARK MATTER; INTERGALACTIC MEDIUM; X-RAYS: GALAXIES full text sources ADS | data products SIMBAD (9) NED (2) HEASARC (1)