PKS 0346−27
| PKS 0346−27 | |
|---|---|
 The blazar PKS 0346−27 | |
| Observation data (J2000.0 epoch) | |
| Constellation | Fornax |
| Right ascension | 03h 48m 38.14s[1] |
| Declination | −27° 49′ 13.56″[1] |
| Redshift | 0.991000[1] |
| Heliocentric radial velocity | 297,094 km/s[1] |
| Distance | 7.891 Gly |
| Apparent magnitude (V) | 18.63 |
| Apparent magnitude (B) | 20.08 |
| Characteristics | |
| Type | FSRQ[1] |
| Other designations | |
| 6dF J0348381−274914, PKS 0346−279, LEDA 2823683, OE −278, NVSS J034838−274914, WMAP 129, 4FGL J0348.6−2749[1] | |
PKS 0346−27 is a blazar located in the constellation of Fornax. Its redshift is (z) 0.991 and as such lies at a distance of 7.8 billion light-years from Earth.[1] This object is also classified as a flat-spectrum radio quasar with its radio spectrum seeming to appear flat with its radio source being first identified in 1966 by astronomers.[2][3]
Description
PKS 0346−27 is highly active on the electromagnetic spectrum in terms of emission of gamma-rays, although it can be categorized as a Low-Synchrotron-Peaked Blazar during its quiescent period because of the low spectral energy distribution peak.[2] On February 2, 2018, it was shown to be in a high-flux state with its gamma-ray flux reaching levels of 1.0 ± 0.2 x 10−6 photons cm−2 s-1 upon detection by Fermi Gamma-ray Space Telescope.[4] The next time the object displayed immense activity, was on April 24, 2019, where it reached a new historic high gamma-ray flux level of 3.2 ± 0.3 x 10−6 photons cm−2 s−1.[5] Subsequently, it displayed more renewed activity recorded in February 2020 and on November 24, 2021.[6][7] An optical flare was also observed, in addition to gamma-rays where the object brightened in brightness.[8][9]
Because of its powerful activity, PKS 0346−27 has been studied in detail. Data from a multiwavelength temporal and spectral study showed the object had multiple flaring episodes based on its gamma-ray light curve analysis from data collected over more than 2 years, with its minimum variability time estimated as 1.34 ± 0.3 days, indicating the source of PKS 0346−27 is compact. Astronomers also suggested the variability of the flares were caused by emission region interactions through stationary shock waves.[10]
It is suggested PKS 0346−27 is a very-high energy emitter. Based on results, it underwent significant flaring activity on November 2, 2021, with a daily flux level of 1.8 ± 0.2 x 10−6 photons cm−2 s−1, an increase of 200 folds since its average flux measured by fourth Fermi-LAT catalogue. The spectral index of the object measured by High Energy Stereoscopic System (HESS) was shown to have a soft index with a unit greater than four.[11]
A quasi-periodic oscillation was detected in PKS 0346−27 during the observations conducted between December 2018 and January 2022. Results showed the periodicity is 100 days long and was likely caused by enhanced radio emission travelling in a helical direction inside a curved radio jet. The supermassive black hole mass was found to be 9.48 x 109 Mʘ.[12]
References
- ^ a b c d e f g "NED search results for PKS 0346-27". NASA/IPAC Extragalactic Database. Retrieved 2025-08-02.
- ^ a b Angioni, R.; Nesci, R.; Finke, J. D.; Buson, S.; Ciprini, S. (July 2019). "The large gamma-ray flare of the flat-spectrum radio quasar PKS 0346-27". Astronomy and Astrophysics. 627: A140. arXiv:1906.08314. Bibcode:2019A&A...627A.140A. doi:10.1051/0004-6361/201935461. ISSN 0004-6361.
- ^ Bolton, J. G.; Ekers, Jennifer (1966). "Identification of radio sources between declinations -20° and -30°". Australian Journal of Physics. 19: 275. Bibcode:1966AuJPh..19..275B. doi:10.1071/PH660275 (inactive 2 August 2025). ISSN 0004-9506.
{{cite journal}}: CS1 maint: DOI inactive as of August 2025 (link) - ^ Angioni, R. (February 2018). "Fermi-LAT detection of strong gamma-ray activity from the FSRQ PKS 0346-27". The Astronomer's Telegram. 11251: 1. Bibcode:2018ATel11251....1A.
- ^ "Fermi-LAT detection of renewed gamma-ray activity from the blazars PKS 0346-27 and PKS 2246+208". The Astronomer's Telegram. Retrieved 2025-08-02.
- ^ La Mura, G.; Prince, R.; Collaboration, Fermi Large Area Telescope (December 2021). "Fermi-LAT and Swift observations of flaring activity from the FSRQ PKS 0346-27". The Astronomer's Telegram. 15092: 1. Bibcode:2021ATel15092....1L.
- ^ Mereu, I. (February 2020). "Fermi-LAT detection of continuing gamma-ray activity from the FSRQ PKS 0346-27". The Astronomer's Telegram. 13521: 1. Bibcode:2020ATel13521....1M.
- ^ "ASAS-SN Discovery of an Unprecedented >1.5 Magnitude Optical Flare from QSO B0346-279". The Astronomer's Telegram. Retrieved 2025-08-02.
- ^ Marchini, Alessandro; Bonnoli, Giacomo; Bellizzi, Lorenzo; Millucci, Vincenzo; Paoletti, Riccardo; Stiaccini, Leonardo; Truzzi, Stefano; Ventura, Sofia; Da Vela, Paolo (February 2019). "Extremely bright optical state of the flaring blazar PKS 0346-27". The Astronomer's Telegram. 12479: 1. Bibcode:2019ATel12479....1M.
- ^ Kamaram, Sushanth Reddy; Prince, Raj; Pramanick, Suman; Bose, Debanjan (2023-01-14). "Multifrequency variability study of flat-spectrum radio quasar PKS 0346-27". Monthly Notices of the Royal Astronomical Society. 520 (2): 2024–2038. doi:10.1093/mnras/stad167. ISSN 0035-8711.
- ^ Malik, Zahoor; Akbar, Sikandar; Shah, Zahir; Misra, Ranjeev; Dar, Athar A; Manzoor, Aaqib; Ahanger, Sajad; Nazir, Zeeshan; Iqbal, Naseer; Rubab, Seemin; Tantry, Javaid (2025-04-15). "Statistical Insights into flux and photon index distributions of VHE FSRQs from Fermi-LAT observations". Monthly Notices of the Royal Astronomical Society. 539 (3): 2185–2201. doi:10.1093/mnras/staf620. ISSN 0035-8711.
- ^ Prince, Raj; Banerjee, Anuvab; Sharma, Ajay; Das, Avik Kumar; Gupta, Alok C.; Bose, Debanjan (2023-10-01). "Quasi-periodic oscillation detected in γ-rays in blazar PKS 0346−27". Astronomy & Astrophysics. 678: A100. arXiv:2308.11317. Bibcode:2023A&A...678A.100P. doi:10.1051/0004-6361/202346400. ISSN 0004-6361.
