Emergence of double-peaked emission lines in the broad-line radio galaxy pictor A

Jules P. Halpern, Michael Eracleous

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

A new optical spectrum of the nearby broad-line radio galaxy (BLRG) Pictor A reveals a prominent double-peaked component of the Balmer lines which does not appear in any historical spectra of this object. Carried out with the hope of obtaining exactly such a result, this observation is a key to the interpretation of double-peaked emitters. It bolsters our previous conclusion that there is a set of additional properties which are associated with the rare class of double-peaked emitters, namely F-R II radio morphology, strong low-ionization forbidden lines, weak UV continuum, and flat far-infrared spectrum. Furthermore, the low-velocity, "ordinary" broad Balmer lines in Pictor A remained relatively unchanged as the new twin peaks appeared, which justifies the practice of applying models that fit only the double peaks and not the low-velocity components that are often present in spectra of this type. We discuss the relative merits of accretion-disk models and other models for double-peaked emission lines in the light of this new observation.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume433
Issue number1 PART 2
StatePublished - Sep 20 1994

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radio galaxies
radio
low speed
emitters
accretion disks
optical spectrum
infrared spectra
continuums
ionization
accretion

All Science Journal Classification (ASJC) codes

  • Space and Planetary Science
  • Nuclear and High Energy Physics

Cite this

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abstract = "A new optical spectrum of the nearby broad-line radio galaxy (BLRG) Pictor A reveals a prominent double-peaked component of the Balmer lines which does not appear in any historical spectra of this object. Carried out with the hope of obtaining exactly such a result, this observation is a key to the interpretation of double-peaked emitters. It bolsters our previous conclusion that there is a set of additional properties which are associated with the rare class of double-peaked emitters, namely F-R II radio morphology, strong low-ionization forbidden lines, weak UV continuum, and flat far-infrared spectrum. Furthermore, the low-velocity, {"}ordinary{"} broad Balmer lines in Pictor A remained relatively unchanged as the new twin peaks appeared, which justifies the practice of applying models that fit only the double peaks and not the low-velocity components that are often present in spectra of this type. We discuss the relative merits of accretion-disk models and other models for double-peaked emission lines in the light of this new observation.",
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Emergence of double-peaked emission lines in the broad-line radio galaxy pictor A. / Halpern, Jules P.; Eracleous, Michael.

In: Astrophysical Journal, Vol. 433, No. 1 PART 2, 20.09.1994.

Research output: Contribution to journalArticle

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T1 - Emergence of double-peaked emission lines in the broad-line radio galaxy pictor A

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N2 - A new optical spectrum of the nearby broad-line radio galaxy (BLRG) Pictor A reveals a prominent double-peaked component of the Balmer lines which does not appear in any historical spectra of this object. Carried out with the hope of obtaining exactly such a result, this observation is a key to the interpretation of double-peaked emitters. It bolsters our previous conclusion that there is a set of additional properties which are associated with the rare class of double-peaked emitters, namely F-R II radio morphology, strong low-ionization forbidden lines, weak UV continuum, and flat far-infrared spectrum. Furthermore, the low-velocity, "ordinary" broad Balmer lines in Pictor A remained relatively unchanged as the new twin peaks appeared, which justifies the practice of applying models that fit only the double peaks and not the low-velocity components that are often present in spectra of this type. We discuss the relative merits of accretion-disk models and other models for double-peaked emission lines in the light of this new observation.

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