NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-24 T06:20:33 PDT
Help | Comment | NED Home

For refcode 2007ApJ...668..150D:
Retrieve 54 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2007ApJ...668..150D The Hot Interstellar Medium of Normal Elliptical Galaxies. I. A Chandra Gas Gallery and Comparison of X-Ray and Optical Morphology Steven Diehl and Thomas S. Statler Abstract. We present an X-ray analysis of 54 normal elliptical galaxies in the Chandra archive and isolate their hot gas component from the contaminating point-source emission, allowing us to conduct, for the first time, a morphological analysis on the gas alone. A comparison with optical images and photometry shows that the hot gas morphology has surprisingly little in common with the shape of the stellar distribution. We observe no correlation between optical and X-ray ellipticities in the inner regions where stellar mass dominates over dark matter. A shallow correlation would be expected if the gas had settled into hydrostatic equilibrium with the gravitational potential. Instead, observed X-ray ellipticities exceed optical ellipticities in many cases. We exclude rotation as the dominant factor to produce the gas ellipticities. The gas appears disturbed, and hydrostatic equilibrium is the exception rather than the rule. Nearly all hydrostatic models can be ruled out at 99% confidence, based on their inability to reproduce the optical -- X-ray correlation and large X-ray ellipticities. Hydrostatic models not excluded are those in which dark matter either dominates over stellar mass inside the inner half-light radius or has a prominently cigar-shaped distribution, both of which can be ruled out on other grounds. We conclude that, even for rather X-ray -- faint elliptical galaxies, the gas is at least so far out of equilibrium that it does not retain any information about the shape of the potential, and that X-ray -- derived radial mass profiles may be in error by factors of order unity. Key words: Galaxies: Cooling Flows, Galaxies: Elliptical and Lenticular, cD, Galaxies: ISM, X-Rays: Galaxies, X-Rays: ISM =========================================================================== 2008ApJ...679.1684D Erratum: "The Hot Interstellar Medium of Normal Elliptical Galaxies. I. A Chandra Gas Gallery and Comparison of X-Ray and Optical Morphology" (ApJ, 668, 150 [2007]) Diehl, Steven; Statler, Thomas S. Abstract. Due to an error in manuscript processing, an extraneous initial digit "1" appears in many of the error bounds in the fourth, fifth, and sixth columns (f_gas_, f_unres_, and f_resol_) of Table 1, and the second column (D) of Table 2 (e.g., 29.2+/-3.8 appears as 29.2+/-13.8). Corrected versions of the tables are given here. The Press sincerely regrets this error. ===========================================================================
Retrieve 54 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home