Multi-frequency Variability Study of Flat-Spectrum Radio Quasar PKS 0346-27

TL;DR

This study analyzes multiwavelength variability of the blazar PKS 0346-27 over two years, identifying flaring episodes, modeling emission mechanisms, and characterizing its variability spectrum, highlighting its potential for future gamma-ray observations.

Contribution

It provides a comprehensive multiwavelength temporal and spectral analysis of PKS 0346-27, including variability timescales, emission modeling, and power spectral density analysis, which is novel for this source.

Findings

Minimum gamma-ray variability timescale of 1.34 days.

Broadband emission explained by synchrotron and SSC, with external Compton dominance at high energies.

Power spectral density slope of 2.15 indicating red noise behavior.

Abstract

We have presented a multiwavelength temporal and spectral study of the Blazar PKS 0346-27 for the period 2019 January-2021 December (MJD 58484-59575) using data from Fermi-LAT (gamma-rays), Swift-XRT (X-rays) and Swift-UVOT (ultra-violet and optical). We identified multiple flaring episodes by analyzing the gamma-ray light curve generated from the Fermi-LAT data over a two-year period. The light curves of these individual gamma-ray flares with one-day binning were then modeled using a sum-of-exponentials fit. We found the minimum variability times for the gamma-ray light curve to be 1.34 +\- 0.3 days and a range of 0.1-3.2 days for the Swift wavelengths suggesting the compactness of the source. The broadband emission mechanism was studied by modeling the simultaneous multi-waveband Spectral Energy Distributions (SED) using the one-zone leptonic emission mechanism. We found that the optical-UV and X-ray data can be explained by the synchrotron and Synchrotron Self-Compton (SSC) emissions. However, the disk component of the External Compton radiation is dominant at higher energies with contributions from the EC broad line region component and SSC. Further, we performed a power spectral density (PSD) analysis with data from the gamma-ray light curve using the power spectrum response (PSRESP) method. With the power law model, a best-fit slope of 2.15 +\- 0.87 was found. This source could be a promising target for upcoming CTA for its harder spectrum at lower energies (tens of GeV).