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Title: NuSTAR, Swift, and GROND Observations of the Flaring MeV Blazar PMN J0641�

Authors:
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Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Aeronautics and Space Administration (NASA)
OSTI Identifier:
1313951
Report Number(s):
SLAC-PUB-16791
Journal ID: ISSN 1538-4357; arXiv:1602.06446
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: The Astrophysical Journal (Online); Journal Volume: 826; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
Astrophysics,ASTRO, GRQC

Citation Formats

Ajello, M., /Clemson U., Ghisellini, G., /Brera Observ., Paliya, V.S., /Clemson U. /Bangalore, Indian Inst. Astrophys., Kocevski, D., /NASA, Goddard, Tagliaferri, G., /Brera Observ., Madejski, G., /KIPAC, Menlo Park, Rau, A., Schady, P., Greiner, J., /Garching, Max Planck Inst., MPE, Massaro, F., /Turin U., Bakolovic, M., /Caltech, Buehler, R., Giomi, M., /DESY, Zeuthen, Marcotulli, L., /Clemson U., D'Ammando, F., /INAF-IRA, Bologna /Bologna U., Dept. Astron., Stern, D., /Caltech, JPL, Boggs, S.E., /UC, Berkeley, Space Sci. Dept., Christensen, F.E., /Danish Space Res. Inst., Craig, W.W., /Danish Space Res. Inst. /LLNL, Livermore, Hailey, C.J., /Columbia U., Harrison, F.A., and /Caltech. /NASA, Goddard. NuSTAR, Swift, and GROND Observations of the Flaring MeV Blazar PMN J0641�. United States: N. p., 2016. Web. doi:10.3847/0004-637X/826/1/76.
Ajello, M., /Clemson U., Ghisellini, G., /Brera Observ., Paliya, V.S., /Clemson U. /Bangalore, Indian Inst. Astrophys., Kocevski, D., /NASA, Goddard, Tagliaferri, G., /Brera Observ., Madejski, G., /KIPAC, Menlo Park, Rau, A., Schady, P., Greiner, J., /Garching, Max Planck Inst., MPE, Massaro, F., /Turin U., Bakolovic, M., /Caltech, Buehler, R., Giomi, M., /DESY, Zeuthen, Marcotulli, L., /Clemson U., D'Ammando, F., /INAF-IRA, Bologna /Bologna U., Dept. Astron., Stern, D., /Caltech, JPL, Boggs, S.E., /UC, Berkeley, Space Sci. Dept., Christensen, F.E., /Danish Space Res. Inst., Craig, W.W., /Danish Space Res. Inst. /LLNL, Livermore, Hailey, C.J., /Columbia U., Harrison, F.A., & /Caltech. /NASA, Goddard. NuSTAR, Swift, and GROND Observations of the Flaring MeV Blazar PMN J0641�. United States. doi:10.3847/0004-637X/826/1/76.
Ajello, M., /Clemson U., Ghisellini, G., /Brera Observ., Paliya, V.S., /Clemson U. /Bangalore, Indian Inst. Astrophys., Kocevski, D., /NASA, Goddard, Tagliaferri, G., /Brera Observ., Madejski, G., /KIPAC, Menlo Park, Rau, A., Schady, P., Greiner, J., /Garching, Max Planck Inst., MPE, Massaro, F., /Turin U., Bakolovic, M., /Caltech, Buehler, R., Giomi, M., /DESY, Zeuthen, Marcotulli, L., /Clemson U., D'Ammando, F., /INAF-IRA, Bologna /Bologna U., Dept. Astron., Stern, D., /Caltech, JPL, Boggs, S.E., /UC, Berkeley, Space Sci. Dept., Christensen, F.E., /Danish Space Res. Inst., Craig, W.W., /Danish Space Res. Inst. /LLNL, Livermore, Hailey, C.J., /Columbia U., Harrison, F.A., and /Caltech. /NASA, Goddard. Fri . "NuSTAR, Swift, and GROND Observations of the Flaring MeV Blazar PMN J0641�". United States. doi:10.3847/0004-637X/826/1/76. https://www.osti.gov/servlets/purl/1313951.
@article{osti_1313951,
title = {NuSTAR, Swift, and GROND Observations of the Flaring MeV Blazar PMN J0641�},
author = {Ajello, M. and /Clemson U. and Ghisellini, G. and /Brera Observ. and Paliya, V.S. and /Clemson U. /Bangalore, Indian Inst. Astrophys. and Kocevski, D. and /NASA, Goddard and Tagliaferri, G. and /Brera Observ. and Madejski, G. and /KIPAC, Menlo Park and Rau, A. and Schady, P. and Greiner, J. and /Garching, Max Planck Inst., MPE and Massaro, F. and /Turin U. and Bakolovic, M. and /Caltech and Buehler, R. and Giomi, M. and /DESY, Zeuthen and Marcotulli, L. and /Clemson U. and D'Ammando, F. and /INAF-IRA, Bologna /Bologna U., Dept. Astron. and Stern, D. and /Caltech, JPL and Boggs, S.E. and /UC, Berkeley, Space Sci. Dept. and Christensen, F.E. and /Danish Space Res. Inst. and Craig, W.W. and /Danish Space Res. Inst. /LLNL, Livermore and Hailey, C.J. and /Columbia U. and Harrison, F.A. and /Caltech. /NASA, Goddard},
abstractNote = {},
doi = {10.3847/0004-637X/826/1/76},
journal = {The Astrophysical Journal (Online)},
number = 1,
volume = 826,
place = {United States},
year = {Fri Aug 19 00:00:00 EDT 2016},
month = {Fri Aug 19 00:00:00 EDT 2016}
}
  • MeV blazars are a sub-population of the blazar family, exhibiting larger-than-average jet powers, accretion luminosities, and black hole masses. Because of their extremely hard X-ray continua, these objects are best studied in the X-ray domain. Here, we report on the discovery by the Fermi Large Area Telescope and subsequent follow-up observations with NuSTAR , Swift , and GROND of a new member of the MeV blazar family: PMN J0641 0320. Our optical spectroscopy provides confirmation that this is a flat-spectrum radio quasar located at a redshift of z = 1.196. Its very hard NuSTAR spectrum (power-law photon index of ∼1more » up to ∼80 keV) indicates that the emission is produced via inverse Compton scattering off of photons coming from outside the jet. The overall spectral energy distribution of PMN J0641 0320 is typical of powerful blazars and, using a simple one-zone leptonic emission model, we infer that the emission region is located either inside the broad line region or within the dusty torus.« less
  • Here we report the results of a multiband observing campaign on the famous blazar 3C 279 conducted during a phase of increased activity from 2013 December to 2014 April, including first observations of it with NuSTAR. The γ-ray emission of the source measured by Fermi-LAT showed multiple distinct flares reaching the highest flux level measured in this object since the beginning of the Fermi mission, with F(E>100 MeV) of 10 -5 photons cm -2 s -1, and with a flux-doubling time scale as short as 2 hr. The γ-ray spectrum during one of the flares was very hard, with an index of Γ γ =1.7±0.1, which is rarely seen in flat-spectrum radio quasars. The lack of concurrent optical variability implies a very high Compton dominance parameter L γ/L syn > 300. Two 1 day NuSTAR observations with accompanying Swift pointings were separated by 2 weeks, probing different levels of source activity. While the 0.5-70 keV X-ray spectrum obtained during the first pointing, and fitted jointly with Swift-XRT is well-described by a simple power law, the second joint observation showed an unusual spectral structure: the spectrum softens by ΔΓ xmore » $$\simeq$$ 0.4 at ~ keV. Modeling the broadband spectral energy distribution during this flare with the standard synchrotron plus inverse-Compton model requires: (1) the location of the γ-ray emitting region is comparable with the broad-line region radius, (2) a very hard electron energy distribution index p $$\simeq$$ 1, (3) total jet power significantly exceeding the accretion-disk luminosity L j/L d ≳ 10, and (4) extremely low jet magnetization with L B/L j ≲ 10 -4. In conclusion, we also find that single-zone models that match the observed γ-ray and optical spectra cannot satisfactorily explain the production of X-ray emission.« less
  • We report the Suzaku observations of the high luminosity blazar SWIFT J0746.3+2548 (J0746) conducted in November 2005. This object, with z = 2.979, is the highest redshift source observed in the Suzaku Guaranteed Time Observer (GTO) period, is likely to show high gamma-ray flux peaking in the MeV range. As a result of the good photon statistics and high signal-to-noise ratio spectrum, the Suzaku observation clearly confirms that J0746 has an extremely hard spectrum in the energy range of 0.3-24 keV, which is well represented by a single power-law with a photon index of {Lambda}{sub ph} {approx_equal} 1.17 and Galacticmore » absorption. The multiwavelength spectral energy distribution of J0746 shows two continuum components, and is well modeled assuming that the high-energy spectral component results from Comptonization of the broad-line region photons. In this paper we search for the bulk Compton spectral features predicted to be produced in the soft X-ray band by scattering external optical/UV photons by cold electrons in a relativistic jet. We discuss and provide constraints on the pair content resulting from the apparent absence of such features.« less
  • Since 2005, the blazar 3C 454.3 has shown remarkable flaring activity at all frequencies, and during the last four years it has exhibited more than one {gamma}-ray flare per year, becoming the most active {gamma}-ray blazar in the sky. We present for the first time the multi-wavelength AGILE, Swift, INTEGRAL, and GASP-WEBT data collected in order to explain the extraordinary {gamma}-ray flare of 3C 454.3 which occurred in 2010 November. On 2010 November 20 (MJD 55520), 3C 454.3 reached a peak flux (E >100 MeV) of F{sup p}{sub {gamma}} = (6.8 {+-} 1.0) x 10{sup -5} photons cm{sup -2} s{supmore » -1} on a timescale of about 12 hr, more than a factor of six higher than the flux of the brightest steady {gamma}-ray source, the Vela pulsar, and more than a factor of three brighter than its previous super-flare on 2009 December 2-3. The multi-wavelength data make possible a thorough study of the present event: the comparison with the previous outbursts indicates a close similarity to the one that occurred in 2009. By comparing the broadband emission before, during, and after the {gamma}-ray flare, we find that the radio, optical, and X-ray emission varies within a factor of 2-3, whereas the {gamma}-ray flux by a factor of 10. This remarkable behavior is modeled by an external Compton component driven by a substantial local enhancement of soft seed photons.« less