Multifrequency studies of the narrow-line Seyfert 1 galaxy SBS 0846+513

Journal Article · Mon Sep 16 00:00:00 EDT 2013 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/stt1560· OSTI ID:1356557

D'Ammando, F. ^[1]; Orienti, M. ^[2]; Finke, J. ^[3]; Raiteri, C. M. ^[4]; Angelakis, E. ^[5]; Fuhrmann, L. ^[5]; Giroletti, M. ^[6]; Hovatta, T. ^[7]; Karamanavis, V. ^[5]; Max-Moerbeck, W. ^[7]; Myserlis, I. ^[5]; Readhead, A. C. S. ^[7]; Richards, J. L. ^[8]

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1. INAF - Istituto di Radioastronomia, Bologna (Italy); Univ. degli Studi di Perugia, Perugia (Italy); INFN Sezione di Perugia, Perugia (Italy)
2. INAF - Istituto di Radioastronomia, Bologna (Italy); Univ. di Bologna, Bologna (Italy)
3. U.S. Naval Research Lab., Washington, D.C. (United States)
4. INAF - Osservatorio Astrofisico di Torino, Pino Torinese (TO) (Italy)
5. Max-Planck-Institut fur Radioastronomie, Bonn (Germany)
6. INAF - Istituto di Radioastronomia, Bologna (Italy)
7. California Inst. of Technology (CalTech), Pasadena, CA (United States)
8. Purdue Univ., West Lafayette, IN (United States)

Here, the narrow-line Seyfert 1 galaxy SBS 0846+513 was first detected by the Large Area Telescope on board Fermi in 2011 June–July when it underwent a period of flaring activity. Since then, as Fermi continues to accumulate data on this source, its flux has been monitored on a daily basis. Two further γ-ray flaring episodes from SBS 0846+513 were observed in 2012 May and August, reaching a daily peak flux integrated above 100 MeV of (50 ± 12) × 10^–8 ph cm^–2 s^–1, and (73 ± 14) × 10^–8 ph cm^–2 s^–1 on May 24 and August 7, respectively. Three outbursts were detected at 15 GHz by the Owens Valley Radio Observatory 40 m telescope in 2012 May, 2012 October and 2013 January, suggesting a complex connection with the γ-ray activity. The most likely scenario suggests that the 2012 May γ-ray flare may not be directly related to the radio activity observed over the same period, while the two γ-ray flaring episodes may be related to the radio activity observed at 15 GHz in 2012 October and 2013 January. The γ-ray flare in 2012 May triggered Swift observations that confirmed that SBS 0846+513 was also exhibiting high activity in the optical, UV and X-ray bands, thus providing a firm identification between the γ-ray source and the lower energy counterpart. We compared the spectral energy distribution (SED) of the flaring state in 2012 May with that of a quiescent state. The two SEDs, modelled as an external Compton component of seed photons from a dust torus, could be fitted by changing the electron distribution parameters as well as the magnetic field. No significant evidence of thermal emission from the accretion disc has been observed. Interestingly, in the 5 GHz radio luminosity versus synchrotron peak frequency plot SBS 0846+513 seems to lie in the flat spectrum radio quasar part of the so-called ‘blazar sequence’.

• Research Organization: SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1356557
• Journal Information: Monthly Notices of the Royal Astronomical Society, Vol. 436, Issue 1; ISSN 0035-8711
• Publisher: Royal Astronomical Society
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
galaxies: active
galaxies: individual: SBS 0846+513
galaxies: nuclei
galaxies: Seyfert
gamma-rays: general