3 years ago

High energy properties of the flat spectrum radio quasar 4C 50.11.

Jianeng Zhou, Zhongxiang Wang, V. Jithesh, Chen Liang

We investigate the $\gamma$-ray and X-ray properties of the flat spectrum radio quasar (FSRQ) \4c50 at redshift $z= 1.517$. The {\it Fermi} Large Area Telescope (LAT) data indicate that this source was in an active state since 2013 July. During the active period, the $\gamma$-ray flux increased by more than a factor of three and two distinct flares were detected with the variability timescale as short as several hours.

The $\gamma$-ray spectra can be well fitted by a log-parabola. From the fitting, we find a correlation between the peak energy and spectral curvature for the $\gamma$-ray spectra, which is the first time seen in $\gamma$-ray emission from a blazar. The {\it Swift} X-ray Telescope (XRT) data show that the source was variable at X-ray energies, but no evidence shows flux or spectral changes related to the $\gamma$-ray activity. The broad-band X-ray spectrum obtained with {\it Swift} XRT and {\it NuSTAR} is well described by a broken PL model, with an extremely hard spectrum ($\Gamma_{1} \sim 0.1$) below the break energy, $E_{\rm break} \sim 2.1 {\rm keV}$, and $\Gamma_{2} \sim 1.5$ above the break energy. The spectral steepening below $\sim 3$ keV is likely due to the low energy cut-off in the energy distribution of the photon-emitting electron population. Both the $\gamma$-ray and X-ray emission appear harder when brighter. The broad-band spectral energy distribution (SED) is constructed for the source, and we provide a model fit to the SED. Our modeling suggests that the emission region should be outside the broad line region, and the properties of the region indicate a jet with 42\% of the Eddington power during the active state.

Publisher URL: http://arxiv.org/abs/1609.09575

DOI: arXiv:1609.09575v3

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.