scholarly journals The relativistic jet of the γ-ray emitting narrow-line Seyfert 1 galaxy 1H 0323+342

2017 ◽  
Vol 475 (1) ◽  
pp. 404-423 ◽  
Author(s):  
Daniel Kynoch ◽  
Hermine Landt ◽  
Martin J Ward ◽  
Chris Done ◽  
Emma Gardner ◽  
...  
Keyword(s):  
2019 ◽  
Vol 487 (1) ◽  
pp. 181-197 ◽  
Author(s):  
Daniel Kynoch ◽  
Hermine Landt ◽  
Martin J Ward ◽  
Chris Done ◽  
Catherine Boisson ◽  
...  

ABSTRACT We present a multifrequency study of PKS J1222+0413 (4C +04.42), currently the highest redshift γ-ray emitting narrow-line Seyfert 1 (γ-NLS1). We assemble a broad spectral energy distribution (SED) including previously unpublished datasets: X-ray data obtained with the NuSTAR and Neil Gehrels Swift observatories; near-infrared, optical, and UV spectroscopy obtained with VLT X-shooter; and multiband radio data from the Effelsberg telescope. These new observations are supplemented by archival data from the literature. We apply physical models to the broad-band SED, parametrizing the accretion flow and jet emission to investigate the disc–jet connection. PKS J1222+0413 has a much greater black hole mass than most other NLS1s, MBH ≈ 2 × 108 M$\odot$, similar to those found in flat spectrum radio quasars (FSRQs). Therefore this source provides insight into how the jets of γ-NLS1s relate to those of FSRQs.


2020 ◽  
Vol 496 (2) ◽  
pp. 2213-2229 ◽  
Author(s):  
F D’Ammando

ABSTRACT We report the analysis of all Swift observations available up to 2019 April of γ-ray-emitting narrow-line Seyfert 1 galaxies (NLSy1). The distribution of X-ray luminosities (and fluxes) indicates that the jet radiation significantly contributes to their X-ray emission, with Doppler boosting making values higher than other radio-loud NLSy1. The 0.3–10 keV photon indices are on average harder with respect to radio-quiet and radio-loud NLSy1, confirming a dominant jet contribution in X-rays. However, the lower variability amplitude with respect to blazars and the softening of the spectrum in some periods suggests that also the corona radiation contributes to the X-ray emission. In optical and ultraviolet (UV) significant flux changes have been observed on daily, weekly, and monthly time-scale, providing a clear indication of the significant contribution of the jet radiation in this part of spectrum. A strong correlation between X-ray, UV, and optical emission and simultaneous flux variations have been observed in 1H 0323+342, SBS 0846+513, PMN J0948+0022 as expected in case the jet radiation is the dominant mechanism. Correlated multiband variability favours the jet-dominated scenario also in FBQS J1644+2619 and PKS 2004−447. The summed X-ray Telescope spectra of 1H 0323+342, SBS 0846+513, PMN J0948+0022, and FBQS J1644+2619 are well fitted by a broken power law with a break around 2 keV. The spectrum above 2 keV is dominated by the non-thermal emission from a beamed relativistic jet, as suggested by the hard photon index. A Seyfert-like feature like the soft X-ray excess has been observed below 2 keV, making these γ-ray-emitting NLSy1 different from typical blazars.


2018 ◽  
Vol 614 ◽  
pp. L1 ◽  
Author(s):  
A. Lähteenmäki ◽  
E. Järvelä ◽  
V. Ramakrishnan ◽  
M. Tornikoski ◽  
J. Tammi ◽  
...  

We have detected six narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz that were previously classified as radio silent and two that were classified as radio quiet. These detections reveal the presumption that NLS1 galaxies labelled radio quiet or radio silent and hosted by spiral galaxies are unable to launch jets to be incorrect. The detections are a plausible indicator of the presence of a powerful, most likely relativistic jet because this intensity of emission at 37 GHz cannot be explained by, for example, radiation from supernova remnants. Additionally, one of the detected NLS1 galaxies is a newly discovered source of gamma rays and three others are candidates for future detections.


Author(s):  
Timothy S Hamilton ◽  
Marco Berton ◽  
Sonia Antón ◽  
Lorenzo Busoni ◽  
Alessandro Caccianiga ◽  
...  

Abstract The γ-ray emitting galaxy SBS 0846 + 513 has been classified as a Narrow-Line Seyfert 1 (NLS1) from its spectroscopy, and on that basis would be thought likely to have a small central black hole hosted in a spiral galaxy. But very few of the γ-ray NLS1 have high-resolution imaging of their hosts, so it is unknown how the morphology expectation holds up for the γ-emitting class. We have observed this galaxy in the J-band with the Large Binocular Telescope’s LUCI1 camera and the ARGOS adaptive optics system. We estimate its black hole mass to lie between $4.2\times 10^7 \le \frac{\text{M}}{\text{M}_\odot } \le 9.7\times 10^7$, using the correlation with bulge luminosity, or $1.9\times 10^7 \le \frac{\text{M}}{\text{M}_\odot } \le 2.4\times 10^7$ using the correlation with Sérsic index. Our favoured estimate is 4.2 × 107M⊙, putting its mass at the high end of the NLS1 range in general but consistent with others that are γ-ray emitters. These estimates are independent of the Broad Line Region viewing geometry and avoid any underestimates due to looking down the jet axis. Its host shows evidence of a bulge + disc structure, from the isophote shape and residual structure in the nuclear-subtracted image. This supports the idea that γ-ray NLS1 may be spiral galaxies, like their non-jetted counterparts.


2018 ◽  
Vol 866 (1) ◽  
pp. 69 ◽  
Author(s):  
Hai-Wu Pan ◽  
Weimin Yuan ◽  
Su Yao ◽  
S. Komossa ◽  
Chichuan Jin
Keyword(s):  
X Ray ◽  

Proceedings ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 9
Author(s):  
Ka-Wah Wong ◽  
Rodrigo S. Nemmen ◽  
Jimmy A. Irwin ◽  
Dacheng Lin

The nearby M87 hosts an exceptional relativistic jet. It has been regularly monitored in radio to TeV bands, but little has been done in hard X-rays ≳10 keV. For the first time, we have successfully detected hard X-rays up to 40 keV from its X-ray core with joint Chandra and NuSTAR observations, providing important insights to the X-ray origins: from the unresolved jet or the accretion flow. We found that the hard X-ray emission is significantly lower than that predicted by synchrotron self-Compton models introduced to explain very-high-energy γ -ray emission above a GeV. We discuss recent models to understand these high energy emission processes.


2014 ◽  
Vol 10 (S313) ◽  
pp. 225-230
Author(s):  
Giulia Migliori

AbstractWe present a multiwavelength study of the core and relativistic jet of the radio loud (RL) quasar RGB J1512+020A (z=0.20). We report the discovery of a bright, 13” extended X-ray jet with a short Chandra observation. We discuss the origin of the jet X-ray emission and its properties in comparison with sample of X-ray quasar jets. The broadband core spectrum is contributed by the emission of the central quasar, by a blazar component, responsible for the γ-ray emission detected by Fermi, and by the host galaxy. We model the non-thermal blazar spectral energy distribution (SED) and constrain the total jet power. The jet power inferred from the blazar SED modeling is in agreement with the values obtained from the total radio power, pointing to a jet that efficiently carries its power up to kiloparsec scales. The quasar emission appears intrinsically weak in the optical-UV band. The disk luminosity estimated from the broad emission lines is lower than the jet power, in agreement with recent results from observations and theory.


2017 ◽  
Vol 469 (1) ◽  
pp. L11-L15 ◽  
Author(s):  
F. D'Ammando ◽  
J. A. Acosta-Pulido ◽  
A. Capetti ◽  
C. M. Raiteri ◽  
R. D. Baldi ◽  
...  
Keyword(s):  

2020 ◽  
Vol 493 (2) ◽  
pp. 1633-1639
Author(s):  
M Saleem

ABSTRACT GW170817 was the first ever joint detection of gravitational waves (GW) from a binary neutron star (BNS) merger with the detections of short γ-ray burst (SGRB) counterparts. Analysis of the multiband afterglow observations of over more than a year revealed that the outflow from the merger end product was consistent with structured relativistic jet models with the core of the jet narrowly collimated to half-opening angles ∼5○. In this work, assuming that all the BNS mergers produce Gaussian structured jets with properties as inferred for GW170817, we explore the prospects of joint detections of BNS mergers and prompt γ-ray emission, expected during the current and upcoming upgrades of LIGO–Virgo–KAGRA detectors. We discuss three specific observational aspects: 1) the distribution of detected binary inclination angles, 2) the distance reach, and 3) the detection rates. Unlike GW-only detections, the joint detections are greatly restricted at large inclination angles, due to the structure of the jets. We find that at lower inclination angles (say below 20○), the distance reach as well as the detection rates of the joint detections are limited by GW detectability while at larger inclinations (say above 20○), they are limited by the γ-ray detectability.


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