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High Resolution Spectroscopy of Cooling Flows: Current Data and Future Prospects. Brian McNamara, John Houck, Claude Canizares, John Davis, Dan Dewey, Larry David, Paul Nulsen, Craig Sarazin, Liz Blanton, Steve Murray, Laura Birzan-Rafferty, David Rafferty, Mangala Sharma. Michael Wise (MIT).
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High Resolution Spectroscopy of CoolingFlows: Current Data and Future Prospects Brian McNamara, John Houck, Claude Canizares, John Davis, Dan Dewey, Larry David, Paul Nulsen, Craig Sarazin, Liz Blanton, Steve Murray, Laura Birzan-Rafferty, David Rafferty, Mangala Sharma Michael Wise (MIT)
Outline • Grating observations of clusters • Technical aspects • Observational complications • Interpreting grating observations • Current limits • Implications • Future prospects • Con-X
2 ~ 1 for all Importance of Spectral Resolution
Observing Clusters with Gratings Identify orders Define extraction region Extract spectrum
Complications for Clusters • Reduced spectral resolution • Complicated wavelength scale • Background estimation difficult • Advanced modeling required
Spatial information possible, but expensive Chandra HETG/LETG Fe XVII : Wise et al. (2003)
XMM RGS Peterson et al. (2003)
RGS limits on Cooling Rates Fe XVII : Peterson et al. (2003)
What limit is interesting? Abell 1068 Star Formation Rate Wise, McNamara, Murray (2003)
Temperature map Absorbing column Wise et al. (2003) H T ~ 0.8 keV Cold Gas M87
Something is either reducing the cooling, or absorbing the emission at low T Sampling the EM distribution Peterson et al. (2003)
Additional physics? • Conduction • Central radio source • Supernovae (Type I and II) • Star formation • Dynamical interactions • Intrinsic absorption Star formation
1000 / 9 Cooling rate limits 200 / 3 40 / 1
Summary • Cooling flows live! • Derived cooling rates are down • Limits not yet restrictive • Imaging clearly shows cool gas • Non-isobaric cooling? • Data imply departures from simple isobaric case • Physical mechanism(s) unclear • Need to measure individual line fluxes • Future Observations • Deeper observations • Con-X