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Title: The Relation Between Accretion Rate And Jet Power in X-Ray Luminous Elliptical Galaxies

Abstract

Using Chandra X-ray observations of nine nearby, X-ray luminous elliptical galaxies with good optical velocity dispersion measurements, we show that a tight correlation exists between the Bondi accretion rates calculated from the observed gas temperature and density profiles and estimated black hole masses, and the power emerging from these systems in relativistic jets. The jet powers, which are inferred from the energies and timescales required to inflate cavities observed in the surrounding X-ray emitting gas, can be related to the accretion rates using a power law model of the form log (P{sub Bondi}/10{sup 43} erg s{sup -1}) = A + B log (P{sub jet}/10{sup 43} erg s{sup -1}), with A = 0.62 {+-} 0.15 and B = 0.77 {+-} 0.18. Our results show that a significant fraction of the energy associated with the rest mass of material entering the Bondi accretion radius (2.4{sub -0.7}{sup +1.0} per cent, for P{sub jet} = 10{sup 43} erg s{sup -1}) eventually emerges in the relativistic jets. Our results have significant implications for studies of accretion, jet formation and galaxy formation. The observed tight correlation suggests that the Bondi formulae provide a reasonable description of the accretion process in these systems, despite the likely presencemore » of magnetic pressure and angular momentum in the accreting gas. The similarity of the P{sub Bondi} and P{sub jet} values argues that a significant fraction of the matter entering the accretion radius flows down to regions close to the black holes, where the jets are presumably formed. The tight correlation between P{sub Bondi} and P{sub jet} also suggests that the accretion flows are approximately stable over timescales of a few million years. Our results show that the black hole ''engines'' at the hearts of large elliptical galaxies and groups feed back sufficient energy to stem cooling and star formation, leading naturally to the observed exponential cut off at the bright end of the galaxy luminosity function.« less

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
877207
Report Number(s):
SLAC-PUB-11738
astro-ph/0602549; TRN: US200608%%145
DOE Contract Number:
AC02-76SF00515
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANGULAR MOMENTUM; BLACK HOLES; CAVITIES; ENGINES; GALAXIES; LUMINOSITY; REST MASS; STARS; VELOCITY; Astrophysics,ASTRO

Citation Formats

Allen, Steven W., /KIPAC, Menlo Park, Dunn, R.J.H., Fabian, A.C., /Cambridge U., Inst. of Astron., Taylor, G.B., /New Mexico U., Reynolds, C.S., and /Maryland U. The Relation Between Accretion Rate And Jet Power in X-Ray Luminous Elliptical Galaxies. United States: N. p., 2006. Web. doi:10.2172/877207.
Allen, Steven W., /KIPAC, Menlo Park, Dunn, R.J.H., Fabian, A.C., /Cambridge U., Inst. of Astron., Taylor, G.B., /New Mexico U., Reynolds, C.S., & /Maryland U. The Relation Between Accretion Rate And Jet Power in X-Ray Luminous Elliptical Galaxies. United States. doi:10.2172/877207.
Allen, Steven W., /KIPAC, Menlo Park, Dunn, R.J.H., Fabian, A.C., /Cambridge U., Inst. of Astron., Taylor, G.B., /New Mexico U., Reynolds, C.S., and /Maryland U. Fri . "The Relation Between Accretion Rate And Jet Power in X-Ray Luminous Elliptical Galaxies". United States. doi:10.2172/877207. https://www.osti.gov/servlets/purl/877207.
@article{osti_877207,
title = {The Relation Between Accretion Rate And Jet Power in X-Ray Luminous Elliptical Galaxies},
author = {Allen, Steven W. and /KIPAC, Menlo Park and Dunn, R.J.H. and Fabian, A.C. and /Cambridge U., Inst. of Astron. and Taylor, G.B. and /New Mexico U. and Reynolds, C.S. and /Maryland U.},
abstractNote = {Using Chandra X-ray observations of nine nearby, X-ray luminous elliptical galaxies with good optical velocity dispersion measurements, we show that a tight correlation exists between the Bondi accretion rates calculated from the observed gas temperature and density profiles and estimated black hole masses, and the power emerging from these systems in relativistic jets. The jet powers, which are inferred from the energies and timescales required to inflate cavities observed in the surrounding X-ray emitting gas, can be related to the accretion rates using a power law model of the form log (P{sub Bondi}/10{sup 43} erg s{sup -1}) = A + B log (P{sub jet}/10{sup 43} erg s{sup -1}), with A = 0.62 {+-} 0.15 and B = 0.77 {+-} 0.18. Our results show that a significant fraction of the energy associated with the rest mass of material entering the Bondi accretion radius (2.4{sub -0.7}{sup +1.0} per cent, for P{sub jet} = 10{sup 43} erg s{sup -1}) eventually emerges in the relativistic jets. Our results have significant implications for studies of accretion, jet formation and galaxy formation. The observed tight correlation suggests that the Bondi formulae provide a reasonable description of the accretion process in these systems, despite the likely presence of magnetic pressure and angular momentum in the accreting gas. The similarity of the P{sub Bondi} and P{sub jet} values argues that a significant fraction of the matter entering the accretion radius flows down to regions close to the black holes, where the jets are presumably formed. The tight correlation between P{sub Bondi} and P{sub jet} also suggests that the accretion flows are approximately stable over timescales of a few million years. Our results show that the black hole ''engines'' at the hearts of large elliptical galaxies and groups feed back sufficient energy to stem cooling and star formation, leading naturally to the observed exponential cut off at the bright end of the galaxy luminosity function.},
doi = {10.2172/877207},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Fri Mar 10 00:00:00 EST 2006},
month = {Fri Mar 10 00:00:00 EST 2006}
}

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  • Ultra-luminous Compact X-ray Sources (ULXs) in nearby spiral galaxies and Galactic superluminal jet sources share the common spectral characteristic that they have unusually high disk temperatures which cannot be explained in the framework of the standard optically thick accretion disk in the Schwarzschild metric. On the other hand, the standard accretion disk around the Kerr black hole might explain the observed high disk temperature, as the inner radius of the Kerr disk gets smaller and the disk temperature can be consequently higher. However, we point out that the observable Kerr disk spectra becomes significantly harder than Schwarzschild disk spectra onlymore » when the disk is highly inclined. This is because the emission from the innermost part of the accretion disk is Doppler-boosted for an edge-on Kerr disk, while hardly seen for a face-on disk. The Galactic superluminal jet sources are known to be highly inclined systems, thus their energy spectra may be explained with the standard Kerr disk with known black hole masses. For ULXs, on the other hand, the standard Kerr disk model seems implausible, since it is highly unlikely that their accretion disks are preferentially inclined, and, if edge-on Kerr disk model is applied, the black hole mass becomes unreasonably large (> 300 M{sub solar}). Instead, the slim disk (advection dominated optically thick disk) model is likely to explain the observed super-Eddington luminosities, hard energy spectra, and spectral variations of ULXs. We suggest that ULXs are accreting black holes with a few tens of solar mass, which is not unexpected from the standard stellar evolution scenario, and that their X-ray emission is from the slim disk shining at super-Eddington luminosities.« less
  • Phenomenological fits to the hard X-ray spectrum of AM Herculis left unexplained the high equivalent width (0.8 + or - 0.1 keV) of Fe K alpha emission. A purely thermal origin implies a much steeper spectrum than was observed. With Monte Carlo calculations, scattering and fluorescent line production in a cold or partially ionized accretion column of hard X-rays emitted at the base were investigated. The strength of the iron emission and the flat spectral continuum can be explained by the effects of fluorescence and absorption within the accretion column and the surface of the white dwarf on a thermalmore » X-ray spectrum. Thomson optical depths across the column in the range 0.2 to 0.7 are acceptable. The accretion rate and gravitational power can be deduced from the optical depth across the column, if the column size is known, and, together with the observed hard X-ray and polarized light luminosities, imply a lower limit for the luminosity in the UV to soft X-ray range, for which the observations give model-dependent values. Estimates of the column size differ by a factor of 40. Small spot sizes and low luminosities would be consistent with the soft component being the expected reprocessed bremsstrahlung and cyclotron radiation, although the constraint of matching the spectrum confines one to solutions with fluxes exceeding 20% the Eddington limits.« less
  • We present new Chandra observations that complete a sample of seventeen (17) luminous infrared galaxies (LIRGs) with D < 60 Mpc and low Galactic column densities of N{sub H} {approx}< 5 x 10{sup 20} cm{sup -2}. The LIRGs in our sample have total infrared (8-1000 {mu}m) luminosities in the range of L{sub IR{approx}} (1-8) x 10{sup 11} L{sub sun}. The high-resolution imaging and X-ray spectral information from our Chandra observations allow us to measure separately X-ray contributions from active galactic nuclei and normal galaxy processes (e.g., X-ray binaries and hot gas). We utilized total infrared plus UV luminosities to estimatemore » star formation rates (SFRs) and K-band luminosities and optical colors to estimate stellar masses (M{sub *}) for the sample. Under the assumption that the galaxy-wide 2-10 keV luminosity (L {sup gal}{sub HX}) traces the combined emission from high-mass X-ray binaries (HMXBs) and low-mass X-ray binaries, and that the power output from these components is linearly correlated with SFR and M{sub *}, respectively, we constrain the relation L {sup gal}{sub HX} = {alpha}M{sub *} + {beta}SFR. To achieve this, we construct a Chandra-based data set composed of our new LIRG sample combined with additional samples of less actively star-forming normal galaxies and more powerful LIRGs and ultraluminous infrared galaxies (ULIRGs) from the literature. Using these data, we measure best-fit values of {alpha} = (9.05 {+-} 0.37) x 10{sup 28} erg s{sup -1} M {sup -1}{sub sun} and {beta} = (1.62 {+-} 0.22) x 10{sup 39} erg s{sup -1} (M{sub sun} yr{sup -1}){sup -1}. This scaling provides a more physically meaningful estimate of L {sup gal}{sub HX}, with {approx}0.1-0.2 dex less scatter, than a direct linear scaling with SFR. Our results suggest that HMXBs dominate the galaxy-wide X-ray emission for galaxies with SFR/M{sub *} {approx}>5.9 x 10{sup -11} yr{sup -1}, a factor of {approx}2.9 times lower than previous estimates. We find that several of the most powerful LIRGs and ULIRGs, with SFR/M{sub *} {approx}> 10{sup -9} yr{sup -1}, appear to be X-ray underluminous with respect to our best-fit relation. We argue that these galaxies are likely to contain X-ray binaries residing in compact star-forming regions that are buried under thick galactic columns large enough to attenuate emission in the 2-10 keV band (N{sub H} {approx}> 10{sup 23} cm{sup -2}).« less