Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

A precessing jet from a supermassive black hole: multi-wavelength observations of S5 1044+71

M. Cerruti, P. A. Duverne, G. Ganesaratnam, P. Goswami, H. X. Ren, N. Sahakyan

Abstract

The bright gamma-ray blazar S5 1044+71 has been identified as showing very significant quasi-periodic oscillations in the Fermi-LAT data in recent studies, with a periodicity of about 3 years. With the completion of a new gamma-ray cycle, we aim to revisit the periodicity in Fermi-LAT data, and analyze all available multi-wavelength (MWL) data to search for possible correlations and time-lags. These observations will be used to test for the compatibility of the observed periodicity with a precessing jet from the supermassive black hole. We analyze data from Fermi-LAT, NuSTAR, Swift, AstroSat, ASAS-SN, ZTF, Pan-STARRS, and NEOWISE. In addition we present an analysis from historical observations from Palomar and Pulkovo. Single-band spectral variability, MWL correlations, and cross-correlations are computed. We then model the Fermi-LAT light curve with a precessing jet model, providing constraints on the geometry of the system and providing the evolution of the Doppler factor with time. The latter is used as input for MWL fitting of the spectral energy distribution. We confirm previous claims on the existence of a periodic gamma-ray signal. We detect significant spectral variability in gamma-ray, X-rays, and optical/UV data. We detect significant correlation between low-energy (infrared/optical/ultraviolet) data and gamma-rays, with a correlation index of about 1; the correlation between X-rays and gamma-ray is milder, with a correlation index of about 0.3. We do not detect any significant time-lag between bands. The Fermi-LAT light curve is successfully fit by a precessing jet model. The fit to the spectral energy distributions indicate that S5 1044+71 is a typical blazar, in which the gamma-ray emission is located beyond the broad-line region. All MWL observations we present in this work are consistent with the existence of a precessing relativistic jet from the supermassive black hole.

A precessing jet from a supermassive black hole: multi-wavelength observations of S5 1044+71

Abstract

The bright gamma-ray blazar S5 1044+71 has been identified as showing very significant quasi-periodic oscillations in the Fermi-LAT data in recent studies, with a periodicity of about 3 years. With the completion of a new gamma-ray cycle, we aim to revisit the periodicity in Fermi-LAT data, and analyze all available multi-wavelength (MWL) data to search for possible correlations and time-lags. These observations will be used to test for the compatibility of the observed periodicity with a precessing jet from the supermassive black hole. We analyze data from Fermi-LAT, NuSTAR, Swift, AstroSat, ASAS-SN, ZTF, Pan-STARRS, and NEOWISE. In addition we present an analysis from historical observations from Palomar and Pulkovo. Single-band spectral variability, MWL correlations, and cross-correlations are computed. We then model the Fermi-LAT light curve with a precessing jet model, providing constraints on the geometry of the system and providing the evolution of the Doppler factor with time. The latter is used as input for MWL fitting of the spectral energy distribution. We confirm previous claims on the existence of a periodic gamma-ray signal. We detect significant spectral variability in gamma-ray, X-rays, and optical/UV data. We detect significant correlation between low-energy (infrared/optical/ultraviolet) data and gamma-rays, with a correlation index of about 1; the correlation between X-rays and gamma-ray is milder, with a correlation index of about 0.3. We do not detect any significant time-lag between bands. The Fermi-LAT light curve is successfully fit by a precessing jet model. The fit to the spectral energy distributions indicate that S5 1044+71 is a typical blazar, in which the gamma-ray emission is located beyond the broad-line region. All MWL observations we present in this work are consistent with the existence of a precessing relativistic jet from the supermassive black hole.
Paper Structure (20 sections, 13 equations, 8 figures, 5 tables)

This paper contains 20 sections, 13 equations, 8 figures, 5 tables.

Table of Contents

  1. Introduction
  2. Multi-wavelength observations
  3. Fermi-LAT
  4. NuSTAR
  5. Swift-XRT
  6. AstroSat-SXT
  7. Swift-UVOT
  8. AstroSat-UVIT
  9. Archival optical and IR data
  10. Historical optical observations: Palomar and Pulkovo
  11. Variability studies
  12. Spectral variability
  13. Multi-wavelength correlations
  14. Time-lags
  15. Periodicity searches
  16. ...and 5 more sections

Figures (8)

  • Figure 1: MWL light curve of S5 1044+71. From top to bottom: Fermi-LAT integral photon flux (100 MeV to 100 GeV) using adaptive binning, and with a fixed 7-day time bin; Swift-XRT and AstroSat X-ray integral energy flux (0.3 keV to 10 keV); Swift-UVOT flux density per filter (split in V,B, and U, and W1, M2, W2, for visibility); optical spectral energy distribution from ASAS-SN, ZTF, and Pan-STARRS; NEOWISE spectral energy distribution at 3.4$\mu m$ and 4.6$\mu m$.
  • Figure 2: Spectral variability in S5 1044+71. From top to bottom: $\gamma$-ray photon index vs the logarithm of the integral photon flux (100 MeV to 100 GeV); X-ray photon index vs the logarithm of the integral photon flux (0.3 keV to 10 keV); optical/UV photon index vs the logarithm of the integral photon flux (from V to W2 UVOT filter).
  • Figure 3: MWL correlation plots with respect to the integral $\gamma$-ray photon flux between 100 MeV and 100 GeV. From top to bottom and left to right, the quantities on the y-axis are: NEOWISE flux at $4.6\mu$m; NEOWISE flux at $3.4\ \mu$m; ZTF i filter flux; ZTF r filter flux; ASAS-SN and ZTF g filter flux; ASAS-SN and UVOT V filter flux; UVOT b filter flux; UVOT u filter flux; UVOT w1 filter flux; UVOT M2 filter flux; UVOT W2 filter flux; XRT and AstroSat-SXT integral photon flux between 0.3 and 10 keV.
  • Figure 4: MWL correlation plots with respect to the $\gamma$-ray spectral energy distribution evaluated at 1 GeV. From top to bottom and left to right, the quantities on the y-axis are: NEOWISE flux at $4.6\mu$m; NEOWISE flux at $3.4\ \mu$m; ZTF i filter flux; ZTF r filter flux; ASAS-SN and ZTF g filter flux; ASAS-SN and UVOT V filter flux; UVOT b filter flux; UVOT u filter flux; UVOT w1 filter flux; UVOT M2 filter flux; UVOT W2 filter flux; XRT and AstroSat-XRT spectral energy distribution evaluated at 1.6 keV.
  • Figure 5: z-transformed discrete correlation function between MWL bands the and the $\gamma$-ray integral photon flux. From top to bottom and left to right, the MWL band used is: ZTF i filter flux; ZTF r filter flux; ASAS-SN and ZTF g filter flux; ASAS-SN and UVOT V filter flux; UVOT b filter flux; UVOT u filter flux; UVOT w1 filter flux; UVOT M2 filter flux; UVOT W2 filter flux; XRT and AstroSat-XRT spectral energy distribution evaluated at 1.6 keV.
  • ...and 3 more figures