Swift detection of all previously undetected blazars in a micro-wave flux-limited sample of WMAP foreground sources

P. Giommi, M. Capalbi, E. Cavazzuti, S. Colafrancesco, A. Cucchiara, A. Falcone, J. Kennea, R. Nesci, M. Perri, G. Tagliaferri, A. Tramacere, G. Tosti, A. J. Blustin, G. Branduardi-Raymont, D. N. Burrows, G. Chincarini, A. J. Dean, N. Gehrels, H. Krimm, F. MarshallA. M. Parsons, B. Zhang

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Almost the totality of the bright foreground sources in the WMAP Cosmic Microwave Background (CMB) maps are blazars, a class of sources that show usually also X-ray emission. However, 23 objects in a flux-limited sample of 140 blazars of the WMAP catalog (first year) were never reported before as X-ray sources. We present here the results of 41 Swift observations which led to the detection of all these 23 blazars in the 0.3-10 keV band. We conclude that all micro-wave selected blazars are X-ray emitters and that the distribution of the micro-wave to X-ray spectral slope (αμx) of LBL blazars is very narrow, confirming that the X-ray flux of most blazars is a very good estimator of their micro-wave emission. The X-ray spectral shape of all the objects that were observed long enough to allow spectral analysis is flat and consistent with inverse Compton emission within the commonly accepted view where the radiation from blazars is emitted in a Syehrotron-Inverse-Compton scenario. We predict that all blazars and most radio galaxies above the sensitivity limit of the WMAP and of the Planck CMB missions are X-ray sources detectable by the present generation of X-ray satellites. An hypothetical all-sky soft X-ray survey with sensitivity of approximately 10-15 erg cm-2 s-1 would be crucial to locate and remove over 100000 blazars from CMB temperature and polarization maps and therefore accurately clean the primordial CMB signal from the largest population of extragalactic foreground contaminants.

Original languageEnglish (US)
Pages (from-to)571-579
Number of pages9
JournalAstronomy and Astrophysics
Volume468
Issue number2
DOIs
StatePublished - Jun 1 2007

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blazars
x rays
microwaves
detection
microwave
microwave emission
sensitivity
radio galaxies
estimators
erg
spectral analysis
catalogs
spectrum analysis
contaminants
sky
emitters
polarization
radio
slopes
pollutant

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Giommi, P. ; Capalbi, M. ; Cavazzuti, E. ; Colafrancesco, S. ; Cucchiara, A. ; Falcone, A. ; Kennea, J. ; Nesci, R. ; Perri, M. ; Tagliaferri, G. ; Tramacere, A. ; Tosti, G. ; Blustin, A. J. ; Branduardi-Raymont, G. ; Burrows, D. N. ; Chincarini, G. ; Dean, A. J. ; Gehrels, N. ; Krimm, H. ; Marshall, F. ; Parsons, A. M. ; Zhang, B. / Swift detection of all previously undetected blazars in a micro-wave flux-limited sample of WMAP foreground sources. In: Astronomy and Astrophysics. 2007 ; Vol. 468, No. 2. pp. 571-579.
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abstract = "Almost the totality of the bright foreground sources in the WMAP Cosmic Microwave Background (CMB) maps are blazars, a class of sources that show usually also X-ray emission. However, 23 objects in a flux-limited sample of 140 blazars of the WMAP catalog (first year) were never reported before as X-ray sources. We present here the results of 41 Swift observations which led to the detection of all these 23 blazars in the 0.3-10 keV band. We conclude that all micro-wave selected blazars are X-ray emitters and that the distribution of the micro-wave to X-ray spectral slope (αμx) of LBL blazars is very narrow, confirming that the X-ray flux of most blazars is a very good estimator of their micro-wave emission. The X-ray spectral shape of all the objects that were observed long enough to allow spectral analysis is flat and consistent with inverse Compton emission within the commonly accepted view where the radiation from blazars is emitted in a Syehrotron-Inverse-Compton scenario. We predict that all blazars and most radio galaxies above the sensitivity limit of the WMAP and of the Planck CMB missions are X-ray sources detectable by the present generation of X-ray satellites. An hypothetical all-sky soft X-ray survey with sensitivity of approximately 10-15 erg cm-2 s-1 would be crucial to locate and remove over 100000 blazars from CMB temperature and polarization maps and therefore accurately clean the primordial CMB signal from the largest population of extragalactic foreground contaminants.",
author = "P. Giommi and M. Capalbi and E. Cavazzuti and S. Colafrancesco and A. Cucchiara and A. Falcone and J. Kennea and R. Nesci and M. Perri and G. Tagliaferri and A. Tramacere and G. Tosti and Blustin, {A. J.} and G. Branduardi-Raymont and Burrows, {D. N.} and G. Chincarini and Dean, {A. J.} and N. Gehrels and H. Krimm and F. Marshall and Parsons, {A. M.} and B. Zhang",
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Giommi, P, Capalbi, M, Cavazzuti, E, Colafrancesco, S, Cucchiara, A, Falcone, A, Kennea, J, Nesci, R, Perri, M, Tagliaferri, G, Tramacere, A, Tosti, G, Blustin, AJ, Branduardi-Raymont, G, Burrows, DN, Chincarini, G, Dean, AJ, Gehrels, N, Krimm, H, Marshall, F, Parsons, AM & Zhang, B 2007, 'Swift detection of all previously undetected blazars in a micro-wave flux-limited sample of WMAP foreground sources', Astronomy and Astrophysics, vol. 468, no. 2, pp. 571-579. https://doi.org/10.1051/0004-6361:20054160

Swift detection of all previously undetected blazars in a micro-wave flux-limited sample of WMAP foreground sources. / Giommi, P.; Capalbi, M.; Cavazzuti, E.; Colafrancesco, S.; Cucchiara, A.; Falcone, A.; Kennea, J.; Nesci, R.; Perri, M.; Tagliaferri, G.; Tramacere, A.; Tosti, G.; Blustin, A. J.; Branduardi-Raymont, G.; Burrows, D. N.; Chincarini, G.; Dean, A. J.; Gehrels, N.; Krimm, H.; Marshall, F.; Parsons, A. M.; Zhang, B.

In: Astronomy and Astrophysics, Vol. 468, No. 2, 01.06.2007, p. 571-579.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Swift detection of all previously undetected blazars in a micro-wave flux-limited sample of WMAP foreground sources

AU - Giommi, P.

AU - Capalbi, M.

AU - Cavazzuti, E.

AU - Colafrancesco, S.

AU - Cucchiara, A.

AU - Falcone, A.

AU - Kennea, J.

AU - Nesci, R.

AU - Perri, M.

AU - Tagliaferri, G.

AU - Tramacere, A.

AU - Tosti, G.

AU - Blustin, A. J.

AU - Branduardi-Raymont, G.

AU - Burrows, D. N.

AU - Chincarini, G.

AU - Dean, A. J.

AU - Gehrels, N.

AU - Krimm, H.

AU - Marshall, F.

AU - Parsons, A. M.

AU - Zhang, B.

PY - 2007/6/1

Y1 - 2007/6/1

N2 - Almost the totality of the bright foreground sources in the WMAP Cosmic Microwave Background (CMB) maps are blazars, a class of sources that show usually also X-ray emission. However, 23 objects in a flux-limited sample of 140 blazars of the WMAP catalog (first year) were never reported before as X-ray sources. We present here the results of 41 Swift observations which led to the detection of all these 23 blazars in the 0.3-10 keV band. We conclude that all micro-wave selected blazars are X-ray emitters and that the distribution of the micro-wave to X-ray spectral slope (αμx) of LBL blazars is very narrow, confirming that the X-ray flux of most blazars is a very good estimator of their micro-wave emission. The X-ray spectral shape of all the objects that were observed long enough to allow spectral analysis is flat and consistent with inverse Compton emission within the commonly accepted view where the radiation from blazars is emitted in a Syehrotron-Inverse-Compton scenario. We predict that all blazars and most radio galaxies above the sensitivity limit of the WMAP and of the Planck CMB missions are X-ray sources detectable by the present generation of X-ray satellites. An hypothetical all-sky soft X-ray survey with sensitivity of approximately 10-15 erg cm-2 s-1 would be crucial to locate and remove over 100000 blazars from CMB temperature and polarization maps and therefore accurately clean the primordial CMB signal from the largest population of extragalactic foreground contaminants.

AB - Almost the totality of the bright foreground sources in the WMAP Cosmic Microwave Background (CMB) maps are blazars, a class of sources that show usually also X-ray emission. However, 23 objects in a flux-limited sample of 140 blazars of the WMAP catalog (first year) were never reported before as X-ray sources. We present here the results of 41 Swift observations which led to the detection of all these 23 blazars in the 0.3-10 keV band. We conclude that all micro-wave selected blazars are X-ray emitters and that the distribution of the micro-wave to X-ray spectral slope (αμx) of LBL blazars is very narrow, confirming that the X-ray flux of most blazars is a very good estimator of their micro-wave emission. The X-ray spectral shape of all the objects that were observed long enough to allow spectral analysis is flat and consistent with inverse Compton emission within the commonly accepted view where the radiation from blazars is emitted in a Syehrotron-Inverse-Compton scenario. We predict that all blazars and most radio galaxies above the sensitivity limit of the WMAP and of the Planck CMB missions are X-ray sources detectable by the present generation of X-ray satellites. An hypothetical all-sky soft X-ray survey with sensitivity of approximately 10-15 erg cm-2 s-1 would be crucial to locate and remove over 100000 blazars from CMB temperature and polarization maps and therefore accurately clean the primordial CMB signal from the largest population of extragalactic foreground contaminants.

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