Long-Term Monitoring of Blazar PKS 0208-512: A Change of γ-Ray Baseline Activity from EGRET to Fermi Era
Abstract
:1. Introduction
2. Observations and Data Analysis
2.1. GeV Data
2.2. X-ray Data
2.2.1. Swift-XRT
2.2.2. AstroSat SXT and LAXPC
2.3. UV/Optical/IR Data
2.4. Archival Data during EGRET Observing Period
3. Results and Discussion
3.1. Broad-Band SED Modeling
Derived SED Parameters during Various Epochs
4. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
1 | https://fermi.gsfc.nasa.gov/cgi-bin/ssc/LAT/LATDataQuery.cgi (accessed on 29 January 2021). |
2 | https://fermipy.readthedocs.io/en/latest/ (accessed on 10 April 2020). |
3 | https://fermi.gsfc.nasa.gov/ssc/data/analysis/user/ (accessed on 10 April 2020). |
4 | https://fermi.gsfc.nasa.gov/ssc/data/analysis/user/ (accessed on 10 April 2020). |
5 | http://astrosat-ssc.iucaa.in/?q=data_and_analysis (accessed on 20 October 2020). |
6 | IRAF is distributed by the National Optical Astronomy Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. |
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Satellite | Energy Band | Flux | Reference a |
---|---|---|---|
ROSAT b | 0.1–2.0 keV | 1 | |
ROSAT b | 0.05–2.5 keV | 2 | |
ASCA b | 2.0–10.0 keV | 3 | |
ASCA b | 0.7–2.0 keV | 3 | |
ASCA b | 0.05–10.0 keV | 4 |
Activity State | Observation Period (MJD) | F a | TS | |||
---|---|---|---|---|---|---|
12 years average | 4 August 2008 (54682)–30 September 2020 (59122) | 53,350.41 | ||||
S1 | 4 August 2008 (54682)–22 April 2018 (58230) | 14,827.87 | ||||
AS1 | 20 Ocotber 2016 (57681)–10 November 2016 (57702) | – | ||||
AS2 | 24 December 2019 (58841)–25 December (58842) | – | <0 |
Activity State | Instrument | Energy Range (keV) | F a | b | /dof |
---|---|---|---|---|---|
AS1 | SXT | 0.6–7 | /67 | ||
LAXPC | 4–20 | 2.86 (UL) | − | − | |
AS2 | SXT | 0.4–7 | 96.75/80 | ||
LAXPC | 4–20 | 7.60/17 |
Activity State | V a | B a | U a | UVW1 a | UVM2 a | UVW2 a |
---|---|---|---|---|---|---|
S1 | ||||||
AS1 * | − | − | ||||
AS2 * | − | − | − | − | − |
Activity State | Filter | (Å) | Flux a |
---|---|---|---|
AS1 | CaF2 (F1) | 1481 | |
Sapphire (F3) | 1608 | ||
NUVN2 (F6) | 2792 | ||
NUVB15 (F2) | 2196 |
Parameter | Symbol | EGRET Time | S1 | AS1 | AS2 |
---|---|---|---|---|---|
Blob size ( cm) | R | ||||
Variability time scale ( sec) | |||||
Location of emission region | r | ||||
(in units of ( cm)) | |||||
Minimum electron Lorentz factor | 170 | 80 | 100 | 100 | |
Maximum electron Lorentz factor | |||||
Break Lorentz factor | |||||
Spectral index (before break) | |||||
Spectral index (after break) | |||||
Normalization of particle spectrum | |||||
Equipartition |
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Ammenadka, K.M.; Bhattacharya, D.; Bhattacharyya, S.; Bhatt, N.; Stalin, C.S. Long-Term Monitoring of Blazar PKS 0208-512: A Change of γ-Ray Baseline Activity from EGRET to Fermi Era. Universe 2022, 8, 534. https://doi.org/10.3390/universe8100534
Ammenadka KM, Bhattacharya D, Bhattacharyya S, Bhatt N, Stalin CS. Long-Term Monitoring of Blazar PKS 0208-512: A Change of γ-Ray Baseline Activity from EGRET to Fermi Era. Universe. 2022; 8(10):534. https://doi.org/10.3390/universe8100534
Chicago/Turabian StyleAmmenadka, Krishna Mohana, Debbijoy Bhattacharya, Subir Bhattacharyya, Nilay Bhatt, and Chelliah Subramonian Stalin. 2022. "Long-Term Monitoring of Blazar PKS 0208-512: A Change of γ-Ray Baseline Activity from EGRET to Fermi Era" Universe 8, no. 10: 534. https://doi.org/10.3390/universe8100534
APA StyleAmmenadka, K. M., Bhattacharya, D., Bhattacharyya, S., Bhatt, N., & Stalin, C. S. (2022). Long-Term Monitoring of Blazar PKS 0208-512: A Change of γ-Ray Baseline Activity from EGRET to Fermi Era. Universe, 8(10), 534. https://doi.org/10.3390/universe8100534