The high-energy spectrum of 3C 273

TL;DR

This study analyzes the high-energy spectrum and variability of 3C 273 across multiple wavelengths, testing leptonic jet models and suggesting alternative origins for X-ray emissions.

Contribution

It provides preliminary multiwavelength spectral analysis of 3C 273, challenging the single-component jet model and proposing a Seyfert-like thermal inverse Compton origin for X-rays.

Findings

Single component model insufficient for full spectrum fit

X-ray emission likely not from jet, possibly Seyfert-like

Spectral variability observed across keV to GeV range

Abstract

The high energy spectral shape of 3C 273 is usually understood in terms of Inverse-Compton emission in a relativistic leptonic jet. This model predicts variability patterns and delays which could be tested if simultaneous observations are available from the infrared to the GeV range. The instruments IBIS, SPI, JEM-X on board INTEGRAL, PCA on board RXTE and LAT on board Fermi have enough sensitivity to follow the spectral variability from the keV to the GeV and to compare them with model predictions. We are presenting preliminary results on the high energy spectrum of 3C 273 and its variability and compare these results to predictions. We found that a single component is not able to adequately fit the multiwavelength spectrum (5 keV - 10 GeV) when the statistics in Fermi data is sufficient to constraint {\gamma}-ray emission. This suggests that the X-rays emission is not originated in the jet. A possible explanation could be that X-rays are dominated by a Seyfert-like thermal inverse Compton.