150 keV emission from PKS 2149-306 with BeppoSAX

Martin Elvis; Fabrizio Fiore; Aneta Siemiginowska; Jill Bechtold; Smita Mathur; Jonathan McDowell

doi:10.1086/317117

150 keV emission from PKS 2149-306 with BeppoSAX

Martin Elvis, Fabrizio Fiore, Aneta Siemiginowska, Jill Bechtold, Smita Mathur, Jonathan McDowell

Steward Observatory

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13 Scopus citations

Abstract

A BeppoSAX observation of the z = 2.34 quasar PKS 2149-306 produced a strong signal in the high-energy PDS instrument up to a maximum observed energy of nearly 50 keV, 150 keV in the quasar frame. The BeppoSAX spectrum spans almost three decades (0.3-150 keV, quasar frame) and shows an extremely hard (α = 0.4 ± 0.05) X-ray spectrum above 3 keV (comparable to XJB the X-ray background slope), and either a softer (α = 1.0^+0.6_-0.3) low-energy component, or an ionized absorber at zero redshift. No evidence is seen of an Fe-K emission line (EW < 167 eV at 6.5 keV quasar frame), a Compton hump (R < 0.3). A bremsstrahlung fit gives kT(rest) = 46⁺³²_-16 keV, similar to the X-ray background value, and a high-energy cut off power law requires E_cut > 120 keV (quasar frame). The SED of PKS 2149-306 shows two peaks at ∼ 10^12±0.5 Hz and ∼ 10^21±1.0 Hz (∼0.3 mm and ∼4 MeV), strongly resembling a low-energy cut off BL Lac object (LBL). The ratio of the two peaks shows an extreme Compton dominance (C_D = 1.4 ± 0.4), as in flat-spectrum radio quasars (FSRQs). The presence of an additional "optical/ UV big bump" component may provide photons that cool the jet, suppressing the radio emission.

Original language	English (US)
Pages (from-to)	545-551
Number of pages	7
Journal	Astrophysical Journal
Volume	543
Issue number	2 PART 1
DOIs	https://doi.org/10.1086/317117
State	Published - Nov 10 2000

Keywords

Gamma rays: observations
Radiation mechanisms: nonthermal
X-rays: galaxies
quasars: general

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1086/317117

Cite this

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title = "150 keV emission from PKS 2149-306 with BeppoSAX",

abstract = "A BeppoSAX observation of the z = 2.34 quasar PKS 2149-306 produced a strong signal in the high-energy PDS instrument up to a maximum observed energy of nearly 50 keV, 150 keV in the quasar frame. The BeppoSAX spectrum spans almost three decades (0.3-150 keV, quasar frame) and shows an extremely hard (α = 0.4 ± 0.05) X-ray spectrum above 3 keV (comparable to XJB the X-ray background slope), and either a softer (α = 1.0+0.6-0.3) low-energy component, or an ionized absorber at zero redshift. No evidence is seen of an Fe-K emission line (EW < 167 eV at 6.5 keV quasar frame), a Compton hump (R < 0.3). A bremsstrahlung fit gives kT(rest) = 46+32-16 keV, similar to the X-ray background value, and a high-energy cut off power law requires Ecut > 120 keV (quasar frame). The SED of PKS 2149-306 shows two peaks at ∼ 1012±0.5 Hz and ∼ 1021±1.0 Hz (∼0.3 mm and ∼4 MeV), strongly resembling a low-energy cut off BL Lac object (LBL). The ratio of the two peaks shows an extreme Compton dominance (CD = 1.4 ± 0.4), as in flat-spectrum radio quasars (FSRQs). The presence of an additional {"}optical/ UV big bump{"} component may provide photons that cool the jet, suppressing the radio emission.",

keywords = "Gamma rays: observations, Radiation mechanisms: nonthermal, X-rays: galaxies, quasars: general",

author = "Martin Elvis and Fabrizio Fiore and Aneta Siemiginowska and Jill Bechtold and Smita Mathur and Jonathan McDowell",

year = "2000",

month = nov,

day = "10",

doi = "10.1086/317117",

language = "English (US)",

volume = "543",

pages = "545--551",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "American Astronomical Society",

number = "2 PART 1",

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T1 - 150 keV emission from PKS 2149-306 with BeppoSAX

AU - Elvis, Martin

AU - Fiore, Fabrizio

AU - Siemiginowska, Aneta

AU - Bechtold, Jill

AU - Mathur, Smita

AU - McDowell, Jonathan

PY - 2000/11/10

Y1 - 2000/11/10

N2 - A BeppoSAX observation of the z = 2.34 quasar PKS 2149-306 produced a strong signal in the high-energy PDS instrument up to a maximum observed energy of nearly 50 keV, 150 keV in the quasar frame. The BeppoSAX spectrum spans almost three decades (0.3-150 keV, quasar frame) and shows an extremely hard (α = 0.4 ± 0.05) X-ray spectrum above 3 keV (comparable to XJB the X-ray background slope), and either a softer (α = 1.0+0.6-0.3) low-energy component, or an ionized absorber at zero redshift. No evidence is seen of an Fe-K emission line (EW < 167 eV at 6.5 keV quasar frame), a Compton hump (R < 0.3). A bremsstrahlung fit gives kT(rest) = 46+32-16 keV, similar to the X-ray background value, and a high-energy cut off power law requires Ecut > 120 keV (quasar frame). The SED of PKS 2149-306 shows two peaks at ∼ 1012±0.5 Hz and ∼ 1021±1.0 Hz (∼0.3 mm and ∼4 MeV), strongly resembling a low-energy cut off BL Lac object (LBL). The ratio of the two peaks shows an extreme Compton dominance (CD = 1.4 ± 0.4), as in flat-spectrum radio quasars (FSRQs). The presence of an additional "optical/ UV big bump" component may provide photons that cool the jet, suppressing the radio emission.

AB - A BeppoSAX observation of the z = 2.34 quasar PKS 2149-306 produced a strong signal in the high-energy PDS instrument up to a maximum observed energy of nearly 50 keV, 150 keV in the quasar frame. The BeppoSAX spectrum spans almost three decades (0.3-150 keV, quasar frame) and shows an extremely hard (α = 0.4 ± 0.05) X-ray spectrum above 3 keV (comparable to XJB the X-ray background slope), and either a softer (α = 1.0+0.6-0.3) low-energy component, or an ionized absorber at zero redshift. No evidence is seen of an Fe-K emission line (EW < 167 eV at 6.5 keV quasar frame), a Compton hump (R < 0.3). A bremsstrahlung fit gives kT(rest) = 46+32-16 keV, similar to the X-ray background value, and a high-energy cut off power law requires Ecut > 120 keV (quasar frame). The SED of PKS 2149-306 shows two peaks at ∼ 1012±0.5 Hz and ∼ 1021±1.0 Hz (∼0.3 mm and ∼4 MeV), strongly resembling a low-energy cut off BL Lac object (LBL). The ratio of the two peaks shows an extreme Compton dominance (CD = 1.4 ± 0.4), as in flat-spectrum radio quasars (FSRQs). The presence of an additional "optical/ UV big bump" component may provide photons that cool the jet, suppressing the radio emission.

KW - Gamma rays: observations

KW - Radiation mechanisms: nonthermal

KW - X-rays: galaxies

KW - quasars: general

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U2 - 10.1086/317117

DO - 10.1086/317117

M3 - Article

AN - SCOPUS:0034634111

SN - 0004-637X

VL - 543

SP - 545

EP - 551

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2 PART 1

ER -

150 keV emission from PKS 2149-306 with BeppoSAX

Abstract

Keywords

ASJC Scopus subject areas

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